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2016-03-28 | A practical guide to density matrix embedding theory in quantum chemistry | Density matrix embedding theory (DMET) provides a theoretical framework to
treat finite fragments in the presence of a surrounding molecular or bulk
environment, even when there is significant correlation or entanglement between
the two. In this work, we give a practically oriented and explicit description
of the numer... | 1603.08443v2 |
2016-03-31 | Five years of density matrix embedding theory | Density matrix embedding theory (DMET) describes finite fragments in the
presence of a surrounding environment. In contrast to most embedding methods,
DMET explicitly allows for quantum entanglement between both. In this chapter,
we discuss both the ground-state and response theory formulations of DMET, and
review seve... | 1605.05547v1 |
2016-05-27 | The Effect of Tetrahedral versus Octahedral Network-Blocking Atom Substitutions on Lithium Ion Conduction in LLZO Garnet | Molecular dynamics calculations are carried out on pure, Al-substituted, and
In-substituted LLZO. The calculations show that the tendency of Al to occupy
the 24d sites in LLZO lithium ion conductors is hypothesized here to negatively
impact ionic conductivity. The room-temperature ionic conductivity of In-LLZO,
in whic... | 1605.08598v1 |
2016-06-18 | Enhanced diffusion and anomalous transport of magnetic colloids driven above a two-state flashing potential | We combine experiment and theory to investigate the diffusive and
subdiffusive dynamics of paramagnetic colloids driven above a two-state
flashing potential. The magnetic potential was realized by periodically
modulating the stray field of a magnetic bubble lattice in a uniaxial ferrite
garnet film. At large amplitudes... | 1606.05783v1 |
2016-07-19 | Electrical detection of spiral spin structures in Pt|Cu_2OSeO_3 heterostructures | The interaction between the itinerant spins in metals and localized spins in
magnetic insulators thus far has only been explored in collinear spin systems,
such as garnets. Here, we report the spin-Hall magnetoresistance (SMR)
sensitive to the surface magnetization of the spin-spiral material, Cu_2OSeO_3.
We experiment... | 1607.05630v1 |
2016-08-03 | Automatic numerical evaluation of vacancy-mediated transport for arbitrary crystals: Onsager coefficients in the dilute limit using a Green function approach | A general solution for vacancy-mediated diffusion in the
dilute-vacancy/dilute-solute limit for arbitrary crystal structures is derived
from the master equation. A general numerical approach to the vacancy lattice
Green function reduces to the sum of a few analytic functions and numerical
integration of a smooth functi... | 1608.01252v2 |
2016-08-11 | Cluster size convergence of the density matrix embedding theory and its dynamical cluster formulation: a study with an auxiliary-field quantum Monte Carlo solver | We investigate the cluster size convergence of the energy and observables
using two forms of density matrix embedding theory (DMET): the original cluster
form (CDMET) and a new formulation motivated by the dynamical cluster
approximation (DCA-DMET). Both methods are applied to the half-filled one- and
two-dimensional H... | 1608.03316v1 |
2016-10-14 | Bidirectional particle transport and size selective sorting of Brownian particles in a flashing spatially periodic energy landscape | We demonstrate a size sensitive experimental scheme which enables
bidirectional transport and fractionation of paramagnetic colloids in a fluid
medium. It is shown that two types of magnetic colloidal particles with
different sizes can be simultaneously transported in opposite directions, when
deposited above a stripe-... | 1610.04380v1 |
2016-10-26 | A general second order complete active space self-consistent-field solver for large-scale systems | We present a new second order complete active space self-consistent field
implementation to converge wavefunctions for both large active spaces and large
atomic orbital (AO) bases. Our algorithm decouples the active space
wavefunction solver from the orbital optimization in the microiterations, and
thus may be easily c... | 1610.08394v2 |
2016-12-02 | Tiny adiabatic-demagnetization refrigerator for a commercial superconducting quantum interference device magnetometer | A tiny adiabatic-demagnetization refrigerator (T-ADR) has been developed for
a commercial superconducting quantum interference device magnetometer [Magnetic
Property Measurement System (MPMS) from Quantum Design]. The whole T-ADR system
is fit in a cylindrical space of the diameter $8.5$ mm and the length $250$ mm,
and... | 1612.01376v1 |
2016-12-31 | Stripe order in the underdoped region of the two-dimensional Hubbard model | Competing inhomogeneous orders are a central feature of correlated electron
materials including the high-temperature superconductors. The two- dimensional
Hubbard model serves as the canonical microscopic physical model for such
systems. Multiple orders have been proposed in the underdoped part of the phase
diagram, wh... | 1701.00054v3 |
2017-01-27 | The Python-based Simulations of Chemistry Framework (PySCF) | PySCF is a general-purpose electronic structure platform designed from the
ground up to emphasize code simplicity, both to aid new method development, as
well as for flexibility in computational workflow. The package provides a wide
range of tools to support simulations of finite size systems, extended systems
with per... | 1701.08223v2 |
2017-03-31 | Time-dependent N-electron valence perturbation theory with matrix product state reference wavefunctions for large active spaces and basis sets: Applications to the chromium dimer and all-trans polyenes | In earlier work [J. Chem. Phys. 144, 064102 (2016)], we introduced a
time-dependent formulation of the second-order N-electron valence perturbation
theory (t-NEVPT2) which (i) had a lower computational scaling than the usual
internally-contracted perturbation formulation, and (ii) yielded the fully
uncontracted NEVPT2 ... | 1703.10830v3 |
2017-05-16 | Bloch line dynamics within moving domain walls in 3D ferromagnets | We study field-driven magnetic domain wall dynamics in garnet strips by
large-scale three-dimensional micromagnetic simulations. The domain wall
propagation velocity as a function of the applied field exhibits a low-field
linear part terminated by a sudden velocity drop at a threshold field
magnitude, related to the on... | 1705.05642v1 |
2017-06-29 | Time-step targeting time-dependent and dynamical density matrix renormalization group algorithms with ab initio Hamiltonians | We study the dynamical density matrix renormalization group (DDMRG) and
time-dependent density matrix renormalization group (td-DMRG) algorithms in the
ab initio context, to compute dynamical correlation functions of correlated
systems. We analyze the strengths and weaknesses of the two methods in small
model problems,... | 1706.09537v2 |
2017-08-01 | Importance sampling large deviations in nonequilibrium steady states. I | Large deviation functions contain information on the stability and response
of systems driven into nonequilibrium steady states, and in such a way are
similar to free energies for systems at equilibrium. As with equilibrium free
energies, evaluating large deviation functions numerically for all but the
simplest systems... | 1708.00459v2 |
2017-08-13 | Experimental study of antiferromagnetic resonance in noncollinear antiferromagnet Mn$_{3}$Al$_{2}$Ge$_{3}$O$_{12}$ | We have measured antiferromagnetic resonance (AFMR) frequency-field
dependences for aluminum-manganese garnet Mn$_{3}$Al$_{2}$Ge$_{3}$O$_{12}$ at
frequencies from 1 to 125 GHz and at the fields up to 60 kOe. Three AFMR modes
were observed for all orientations, their zero field gaps are about 40 and 70
GHz. Andreev-Marc... | 1708.03961v1 |
2017-08-16 | Anisotropic phase diagram and spin fluctuations of the hyperkagome magnet Gd3Ga5O12 as revealed by sound velocity measurements | Sound velocity and attenuation measurements on the frustrated garnet material
Gd3Ga5O12 (GGG) are presented as a function of field and temperature, using two
different acoustic modes and with two different magnetic field orientations:
[100] and [110]. We demonstrate that the phase diagram is highly anisotropic,
with tw... | 1708.04916v2 |
2017-08-30 | Exact fluctuations of nonequilibrium steady states from approximate auxiliary dynamics | We describe a framework to significantly reduce the computational effort to
evaluate large deviation functions of time integrated observables within
nonequilibrium steady states. We do this by incorporating an auxiliary dynamics
into trajectory based Monte Carlo calculations, through a transformation of the
system's pr... | 1708.09482v4 |
2017-09-06 | Superposition as a Relativistic Filter | By associating a binary signal with the relativistic worldline of a particle,
a binary form of the phase of non-relativistic wavefunctions is naturally
produced by time dilation. An analog of superposition also appears as a Lorentz
filtering process, removing paths that are relativistically inequivalent. In a
model tha... | 1709.02022v1 |
2017-10-23 | Frequency and wavenumber selective excitation of spin waves through coherent energy transfer from elastic waves | Using spin-wave tomography (SWaT), we have investigated the excitation and
the propagation dynamics of optically-excited magnetoelastic waves, i.e.
hybridized modes of spin waves and elastic waves, in a garnet film. By using
time-resolved SWaT, we reveal the excitation dynamics of magnetoelastic waves
through coherent-... | 1710.08087v2 |
2017-10-27 | Nuclear Magnetic Resonance in Noncollinear Antiferromagnet Mn3Al2Ge3O12 | The 55Mn nuclear magnetic resonance spectrum of noncollinear 12-sublattice
antiferromagnet Mn3Al2Ge3O12 has been studied in the frequency range of 200 -
640 MHz in the external magnetic field H || [001]} at T=1.2 K. Three absorption
lines have been observed in fields less than the field of the reorientation
transition ... | 1710.10048v1 |
2017-11-13 | Quantum Simulation of Electronic Structure with Linear Depth and Connectivity | As physical implementations of quantum architectures emerge, it is
increasingly important to consider the cost of algorithms for practical
connectivities between qubits. We show that by using an arrangement of gates
that we term the fermionic swap network, we can simulate a Trotter step of the
electronic structure Hami... | 1711.04789v2 |
2017-12-04 | Phase-resolved Spin-Wave Tomography | The propagation dynamics of spin waves are represented by their dispersion
relations. Recently, we have developed a method, called spin-wave tomography
(SWaT), to obtain dispersion relation of spin waves in the long wavelength
regime, so-called pure magnetostatic waves. In our previous studies on SWaT,
phase informatio... | 1712.00927v2 |
2017-12-05 | Surface plasmon-mediated nanoscale localization of laser-driven sub-THz spin dynamics in magnetic dielectrics | Ultrafast all-optical control of spins with femtosecond laser pulses is one
of the hot topics at the crossroads of photonics and magnetism with a direct
impact on future magnetic recording. Unveiling light-assisted recording
mechanisms for an increase of the bit density beyond the diffraction limit
without excessive he... | 1712.01617v1 |
2017-12-27 | Progress on the design of a perpendicularly biased 2nd harmonic cavity for the Fermilab Booster | A perpendicularly biased 2nd harmonic cavity is being designed and built for
the Fermilab Booster. Its purpose is to flatten the bucket at injection and
thus change the longitudinal beam distribution to decrease space charge
effects. It can also help at extraction. The cavity frequency range is 76 - 106
MHz. The power ... | 1712.09637v1 |
2018-03-21 | 180-degree phase shift of magnetoelastic waves observed by phase-resolved spin-wave tomography | We have investigated optically-excited magnetoelastic waves by phase-resolved
spin-wave tomography (PSWaT). PSWaT reconstructs dispersion relation of spin
waves together with their phase information by using time-resolved
magneto-optical imaging for spin-wave propagation followed by an analysis based
on the convolution... | 1803.07697v1 |
2018-04-14 | Particle Morphology and Lithium Segregation to Surfaces of the Li$_7$La$_3$Zr$_2$O$_{12}$ Solid Electrolyte | Solid electrolytes for solid-state Li-ion batteries are stimulating
considerable interest for next-generation energy storage applications. The
Li$_7$La$_3$Zr$_2$O$_{12}$ garnet-type solid electrolyte has received
appreciable attention as a result of its high ionic conductivity. However,
several challenges for the succe... | 1804.05165v1 |
2018-06-19 | Time-Dependent Density Matrix Renormalization Group Algorithms for Nearly Exact Absorption and Fluorescence Spectra of Molecular Aggregates at Both Zero and Finite Temperature | We implement and apply time-dependent density matrix renormalization group
(TD-DMRG) algorithms at zero and finite temperature to compute the linear
absorption and fluorescence spectra of molecular aggregates. Our implementation
is within a matrix product state/operator framework with an explicit treatment
of the excit... | 1806.07443v2 |
2018-07-22 | Efficient representation of long-range interactions in tensor network algorithms | We describe a practical and efficient approach to represent physically
realistic long-range interactions in two-dimensional tensor network algorithms
via projected entangled-pair operators (PEPOs). We express the long-range
interaction as a linear combination of correlation functions of an auxiliary
system with only ne... | 1807.08378v2 |
2018-07-26 | A time-dependent formulation of coupled cluster theory for many-fermion systems at finite temperature | We present a time-dependent formulation of coupled cluster theory. This
theory allows for direct computation of the free energy of quantum systems at
finite temperature by imaginary time integration and is closely related to the
thermal cluster cumulant theory of Mukherjee and co-workers. Our derivation
highlights the ... | 1807.09961v2 |
2018-08-28 | The FNAL Booster 2nd Harmonic RF Cavity | A second harmonic RF cavity which uses perpendicularly biased garnet for
frequency tuning is currently being constructed for use in the Fermilab
Booster. The cavity will operate at twice the fundamental RF frequency, from
~76 - 106 MHz, and will be turned on only during injection, and transition or
extraction. Its main... | 1808.09513v1 |
2018-09-27 | The electronic complexity of the ground-state of the FeMo cofactor of nitrogenase as relevant to quantum simulations | We report that a recent active space model of the nitrogenase FeMo cofactor,
proposed in the context of quantum simulations, is not representative of the
electronic structure of the FeMo cofactor ground-state. Although quantum
resource estimates, outside of the cost of adiabatic state preparation, will
not be much affe... | 1809.10307v1 |
2018-10-03 | Efficient ab initio auxiliary-field quantum Monte Carlo calculations in Gaussian bases via low-rank tensor decomposition | We describe an algorithm to reduce the cost of auxiliary-field quantum Monte
Carlo (AFQMC) calculations for the electronic structure problem. The technique
uses a nested low-rank factorization of the electron repulsion integral (ERI).
While the cost of conventional AFQMC calculations in Gaussian bases scales as
$\mathc... | 1810.01549v2 |
2018-11-14 | Enhancing nanoparticle diffusion on a unidirectional domain wall magnetic ratchet | The performance of nanoscale magnetic devices is often limited by the
presence of thermal fluctuations, while in micro-nanofluidic applications the
same fluctuations may be used to spread reactants or drugs. Here we demonstrate
the controlled motion and the enhancement of diffusion of magnetic
nanoparticles that are ma... | 1811.05762v1 |
2019-01-17 | Statistical Mechanics and the Ghosts of Departed Quantities | Quantum mechanics appears to contain ghosts from both classical statistical
mechanics and special relativity. On one hand, both the Dirac and
Schr\"{o}dinger equations have classical analogs that emerge directly from
classical statistical mechanics, unimpeded by major problems of interpretation.
On the other hand, the ... | 1901.11066v1 |
2019-01-25 | Monolithic integration of broadband optical isolators for polarization-diverse silicon photonics | Integrated optical isolators have been a longstanding challenge for photonic
integrated circuits (PIC). An ideal integrated optical isolator for PIC should
be made by a monolithic process, have a small footprint, exhibit broadband and
polarization-diverse operation, and be compatible with multiple materials
platforms. ... | 1902.01236v1 |
2019-03-09 | Conversion of projected entangled pair states into a canonical form | We propose an algorithm to convert a projected entangled pair state (PEPS)
into a canonical form, analogous to the well-known canonical form of a matrix
product state. Our approach is based on a variational gauging ansatz for the QR
tensor decomposition of PEPS columns into a matrix product operator and a
finite depth ... | 1903.03843v4 |
2019-04-15 | Dynamical phase behavior of the single- and multi-lane asymmetric simple exclusion process via matrix product states | We analyze the dynamical phases of the current-biased 1D and multi-lane open
asymmetric simple exclusion processes (ASEP), using matrix product states and
the density matrix renormalization group (DMRG) algorithm. In the 1D ASEP, we
present a systematic numerical study of the current cumulant generating
function and it... | 1904.07336v1 |
2019-05-01 | Hamiltonian symmetries in auxiliary-field quantum Monte Carlo calculations for electronic structure | We describe how to incorporate symmetries of the Hamiltonian into
auxiliary-field quantum Monte Carlo calculations (AFQMC). Focusing on the case
of Abelian symmetries, we show that the computational cost of most steps of an
AFQMC calculation is reduced by $N_k^{-1}$, where $N_k$ is the number of
irreducible representat... | 1905.00511v1 |
2019-05-28 | Coupled-cluster impurity solvers for dynamical mean-field theory | We describe the use of coupled-cluster theory as an impurity solver in
dynamical mean-field theory (DMFT) and its cluster extensions. We present
numerical results at the level of coupled-cluster theory with single and double
excitations (CCSD) for the density of states and self-energies of cluster
impurity problems in ... | 1905.12050v2 |
2019-08-14 | A Tuneable Magnetic Domain Wall Conduit Regulating Nanoparticle Diffusion | We demonstrate a general and robust method to confine on a plane strongly
diffusing submicrometer particles in water by using size tunable magnetic
channels. These virtual conduits are realized with pairs of movable Bloch walls
(BWs) located within an epitaxially grown ferrite garnet film. We show that,
once inside the... | 1908.05039v1 |
2019-09-18 | Efficient Formulation of Ab Initio Quantum Embedding in Periodic Systems: Dynamical Mean-Field Theory | We present an efficient ab initio dynamical mean-field theory (DMFT)
implementation for quantitative simulations in solids. Our DMFT scheme employs
ab initio Hamiltonians defined for impurities comprising the full unit cell or
a supercell of atoms and for realistic quantum chemical basis sets. We avoid
double counting ... | 1909.08592v2 |
2019-09-18 | Efficient Implementation of Ab Initio Quantum Embedding in Periodic Systems: Density Matrix Embedding Theory | We describe an efficient quantum embedding framework for realistic ab initio
density matrix embedding (DMET) calculations in solids. We discuss in detail
the choice of orbitals and mapping to a lattice, treatment of the virtual space
and bath truncation, and the lattice-to embedded integral transformation. We
apply DME... | 1909.08596v2 |
2019-09-24 | First principles coupled cluster theory of the electronic spectrum of the transition metal dichalcogenides | The electronic properties of two-dimensional transition metal dichalcogenides
(2D TMDs) have attracted much attention during the last decade. We show how a
diagrammatic ab initio coupled cluster singles and doubles (CCSD) treatment
paired with a careful thermodynamic limit extrapolation in two dimensions can
be used to... | 1909.10886v1 |
2019-09-25 | Constructing Auxiliary Dynamics for Nonequilibrium Stationary States by Variance Minimization | We present a strategy to construct guiding distribution functions (GDFs)
based on variance minimization. Auxiliary dynamics via GDFs mitigates the
exponential growth of variance as a function of bias in Monte Carlo estimators
of large deviation functions. The variance minimization technique exploits the
exact propertie... | 1909.11283v3 |
2019-10-22 | Exact Parameterization of Fermionic Wave Functions via Unitary Coupled Cluster Theory | A formal analysis is conducted on the exactness of various forms of unitary
coupled cluster (UCC) theory based on particle-hole excitation and
de-excitation operators. Both the conventional single exponential UCC
parameterization and a disentangled (factorized) version are considered. We
formulate a differential cluste... | 1910.10130v1 |
2019-11-18 | Finite temperature density matrix embedding theory | We describe a formulation of the density matrix embedding theory at finite
temperature. We present a generalization of the ground-state bath orbital
construction that embeds a mean-field finite-temperature density matrix up to a
given order in the Hamiltonian, or the Hamiltonian up to a given order in the
density matri... | 1911.07439v1 |
2019-12-27 | Ferromagnetic state above room temperature in a proximitized topological Dirac semimetal | We report an above-room-temperature ferromagnetic state realized in a
proximitized Dirac semimetal, which is fabricated by growing typical Dirac
semimetal Cd$_3$As$_2$ films on a ferromagnetic garnet with strong
perpendicular magnetization. Observed anomalous Hall conductivity with
substantially large Hall angles is fo... | 1912.11964v1 |
2020-01-01 | Exploring the magnetic properties of the largest single molecule magnets | The giant $\{ \mathrm{Mn}_{70} \}$ and $\{ \mathrm{Mn}_{84} \}$ wheels are
the largest nuclearity single-molecule magnets synthesized to date and
understanding their magnetic properties poses a challenge to theory. Starting
from first principles calculations, we explore the magnetic properties and
excitations in these ... | 2001.00247v2 |
2020-01-14 | Invariable generation and wreath products | Invariable generation is a topic that has predominantly been studied for
finite groups. In 2014, Kantor, Lubotzky, and Shalev produced extensive tools
for investigating invariable generation for infinite groups. Since their paper,
various authors have investigated the property for particular infinite groups
or families... | 2001.04748v3 |
2020-04-03 | Finite-temperature coupled cluster: Efficient implementation and application to prototypical systems | We discuss the theory and implementation of the finite temperature coupled
cluster singles and doubles (FT-CCSD) method including the equations necessary
for an efficient implementation of response properties. Numerical aspects of
the method including the truncation of the orbital space and integration of the
amplitude... | 2004.01729v1 |
2020-04-18 | Novel algorithms and high-performance cloud computing enable efficient fully quantum mechanical protein-ligand scoring | Ranking the binding of small molecules to protein receptors through
physics-based computation remains challenging. Though inroads have been made
using free energy methods, these fail when the underlying classical mechanical
force fields are insufficient. In principle, a more accurate approach is
provided by quantum mec... | 2004.08725v1 |
2020-05-07 | Minimal matrix product states and generalizations of mean-field and geminal wavefunctions | Simple wavefunctions of low computational cost but which can achieve
qualitative accuracy across the whole potential energy surface (PES) are of
relevance to many areas of electronic structure as well as to applications to
dynamics. Here, we explore a class of simple wavefunctions, the minimal matrix
product state (MMP... | 2005.03703v2 |
2020-05-18 | Optical properties of YAG:Ce and GGG:Ce scintillation crystals irradiated with a high fluence proton beam | In this paper, we report on the study of the optical properties of YAG:Ce and
GGG:Ce garnet crystals after irradiation in a 660~MeV proton beam with a
fluence up to 8.9$\times$10$^{14}$ protons/cm$^2$. We found that the
transparency of both crystals fell by no more than 7\% in the region of their
own luminescence. The ... | 2005.09087v1 |
2020-07-03 | Invariable generation and the Houghton groups | The Houghton groups $H_1, H_2, \ldots$ are a family of infinite groups. In
1975 Wiegold showed that $H_3$ was invariably generated (IG) but $H_1\le H_3$
was not. A natural question is then whether the groups $H_2, H_3, \ldots$ are
all IG. Wiegold also ends by saying that, in the examples he had found of an IG
group wit... | 2007.01626v1 |
2020-08-24 | Numerical continuum tensor networks in two dimensions | We describe the use of tensor networks to numerically determine wave
functions of interacting two-dimensional fermionic models in the continuum
limit. We use two different tensor network states: one based on the numerical
continuum limit of fermionic projected entangled pair states obtained via a
tensor network formula... | 2008.10566v1 |
2020-08-25 | Short-range Thermal Magnon Diffusion in Magnetic Garnet | Using the spin Seebeck effect (SSE), we study the propagation distance of
thermal spin currents inside a magnetic insulator thin film in the short-range
regime. We disambiguate spin currents driven by temperature and chemical
potential gradients by comparing the SSE signal before and after adding a
thermalization cappi... | 2008.10942v1 |
2020-09-08 | Quantum Computation of Finite-Temperature Static and Dynamical Properties of Spin Systems Using Quantum Imaginary Time Evolution | Developing scalable quantum algorithms to study finite-temperature physics of
quantum many-body systems has attracted considerable interest due to recent
advancements in quantum hardware. However, such algorithms in their present
form require resources that exceed the capabilities of current quantum
computers except fo... | 2009.03542v1 |
2020-09-28 | A coupled cluster framework for electrons and phonons | We describe a coupled cluster framework for coupled systems of electrons and
phonons. Neutral and charged excitations are accessed via the
equation-of-motion version of the theory. Benchmarks on the Hubbard-Holstein
model allow us to assess the strengths and weaknesses of different coupled
cluster approximations which ... | 2009.13568v2 |
2020-10-26 | Ultrafast phononic switching of magnetization | Identifying an efficient pathway to change the order parameter via a subtle
excitation of the coupled high-frequency mode is the ultimate goal of the field
of ultrafast phase transitions. This is an especially interesting research
direction in magnetism, where the coupling between spin and lattice excitations
is requir... | 2010.13671v1 |
2021-01-14 | Constructing Tensor Network Influence Functionals for General Quantum Dynamics | We describe an iterative formalism to compute influence functionals that
describe the general quantum dynamics of a subsystem beyond the assumption of
linear coupling to a quadratic bath. We use a space-time tensor network
representation of the influence functional and investigate its approximability
in terms of the bo... | 2101.05466v3 |
2021-01-28 | On the finite index subgroups of Houghton's groups | An erratum has been added to resolve an issue raised by Professor Derek Holt.
This appears after the original paper, and also includes two new results.
Original abstract: Houghton's groups $H_2, H_3, \ldots$ are certain infinite
permutation groups acting on a countably infinite set; they have been studied,
among othe... | 2101.12116v5 |
2021-02-07 | Characterization and identification of Au pathfinder minerals from an artisanal mine site using X-ray diffraction | Gold-associated pathfinder minerals have been investigated by identifying
host minerals of Au for samples collected from an artisanal mining site near a
potential gold mine (Kubi Gold Project) in Dunkwa-On-Offin in the central
region of Ghana. We find that for each composition of Au powder (impure) and
the residual bla... | 2102.03744v1 |
2021-02-25 | Externally corrected CCSD with renormalized perturbative triples (R-ecCCSD(T)) and density matrix renormalization group and selected configuration interaction external sources | We investigate the renormalized perturbative triples correction together with
the externally corrected coupled-cluster singles and doubles (ecCCSD) method.
We take the density matrix renormalization group (DMRG) and heatbath CI (HCI)
as external sources for the ecCCSD equations. The accuracy is assessed for the
potenti... | 2102.12703v1 |
2021-03-18 | Low communication high performance ab initio density matrix renormalization group algorithms | There has been recent interest in the deployment of ab initio density matrix
renormalization group computations on high performance computing platforms.
Here, we introduce a reformulation of the conventional distributed memory ab
initio DMRG algorithm that connects it to the conceptually simpler and
advantageous sum of... | 2103.09976v3 |
2021-04-02 | Surface plasmon-enhanced photo-magnetic excitation of spin dynamics in Au/YIG:Co magneto-plasmonic crystals | We report strong amplification of photo-magnetic spin precession in Co-doped
YIG employing a surface plasmon excitation in a metal-dielectric
magneto-plasmonic crystal. Plasmonic enhancement is accompanied by the
localization of the excitation within the 300~nm-thick layer inside the
transparent dielectric garnet. Expe... | 2104.01250v1 |
2021-04-14 | Spin waves propagating through a stripe magnetic domain structure and their applications to reservoir computing | Spin waves propagating through a stripe domain structure and reservoir
computing with their spin dynamics have been numerically studied with focusing
on the relation between physical phenomena and computing capabilities. Our
system utilizes a spin-wave-based device that has a continuous magnetic garnet
film and 1-input... | 2104.06794v1 |
2021-04-28 | The Fermionic Quantum Emulator | The fermionic quantum emulator (FQE) is a collection of protocols for
emulating quantum dynamics of fermions efficiently taking advantage of common
symmetries present in chemical, materials, and condensed-matter systems. The
library is fully integrated with the OpenFermion software package and serves as
the simulation ... | 2104.13944v2 |
2021-06-04 | Conservation laws in coupled cluster dynamics at finite-temperature | We extend the finite-temperature Keldysh non-equilibrium coupled cluster
theory (Keldysh-CC) [{\it J. Chem. Theory Comput.} \textbf{2019}, 15,
6137-6253] to include a time-dependent orbital basis. When chosen to minimize
the action, such a basis restores local and global conservation laws
(Ehrenfest's theorem) for all ... | 2106.02691v1 |
2021-06-08 | Implications of PREX--2 data on the electron--neutrino opacity in dense matter | Motivated by the recent measurement of the neutron distribution radius of
${}^{208}$Pb from the PREX--2 data, I study the effects of the new G3(M)
parameter set constrained by PREX--2 data on the electron--neutrino scattering
in dense matter using the extended relativistic mean field (E--RMF) model. I
employ the G3(M) ... | 2106.04474v2 |
2021-07-03 | The Variational Power of Quantum Circuit Tensor Networks | We characterize the variational power of quantum circuit tensor networks in
the representation of physical many-body ground-states. Such tensor networks
are formed by replacing the dense block unitaries and isometries in standard
tensor networks by local quantum circuits. We explore both quantum circuit
matrix product ... | 2107.01307v2 |
2021-09-22 | Matrix product states with large sites | We explore various ways to group orbitals into clusters in a matrix product
state (MPS). We explain how a generic cluster MPS can often lead to an increase
in computational cost and instead propose a special cluster structure,
involving only the first and last orbitals/sites, with a wider scope for
computational advant... | 2109.11036v2 |
2021-10-18 | On the pure state $v$-representability of density matrix embedding theory | Density matrix embedding theory (DMET) formally requires the matching of
density matrix blocks obtained from high-level and low-level theories, but this
is sometimes not achievable in practical calculations. In such a case, the
global band gap of the low-level theory vanishes, and this can require
additional numerical ... | 2110.09558v2 |
2021-11-23 | Quantum harmonic free energies for biomolecules and nanomaterials | Obtaining the free energy of large molecules from quantum mechanical energy
functions is a longstanding challenge. We describe a method that allows us to
estimate, at the quantum mechanical level, the harmonic contributions to the
thermodynamics of molecular systems of large size, with modest cost. Using this
approach,... | 2111.12200v2 |
2021-12-17 | Systematic electronic structure in the cuprate parent state from quantum many-body simulations | The quantitative description of correlated electron materials remains a
modern computational challenge. We demonstrate a numerical strategy to simulate
correlated materials at the fully ab initio level beyond the solution of
effective low-energy models, and apply it to gain a detailed microscopic
understanding across a... | 2112.09735v3 |
2021-12-20 | Realizing symmetry-protected topological phases in a spin-1/2 chain with next-nearest neighbor hopping on superconducting qubits | The realization of novel phases of matter on quantum simulators is a topic of
intense interest. Digital quantum computers offer a route to prepare
topological phases with interactions that do not naturally arise in analog
quantum simulators. Here, we report the realization of symmetry-protected
topological (SPT) phases... | 2112.10333v1 |
2021-12-20 | Holographic simulation of correlated electrons on a trapped ion quantum processor | We develop holographic quantum simulation techniques to prepare correlated
electronic ground states in quantum matrix product state (qMPS) form, using far
fewer qubits than the number of orbitals represented. Our approach starts with
a holographic technique to prepare a compressed approximation to electronic
mean-field... | 2112.10810v3 |
2022-01-10 | Entanglement in the quantum phases of an unfrustrated Rydberg atom array | We report on the ground state phase diagram of interacting Rydberg atoms in
the unfrustrated square lattice array. Using new tensor network algorithms, we
scale to large systems in two dimensions while including all long-range
interactions, revealing the phases in the bulk and their analogs in accessible
finite arrays.... | 2201.03189v1 |
2022-06-14 | Hyper-optimized approximate contraction of tensor networks with arbitrary geometry | Tensor network contraction is central to problems ranging from many-body
physics to computer science. We describe how to approximate tensor network
contraction through bond compression on arbitrary graphs. In particular, we
introduce a hyper-optimization over the compression and contraction strategy
itself to minimize ... | 2206.07044v2 |
2022-06-21 | The chromium dimer: closing a chapter of quantum chemistry | The complex electronic structure and unusual potential energy curve of the
chromium dimer have fascinated scientists for decades, with agreement between
theory and experiment so far elusive. Here, we present a new ab initio
simulation of the potential energy curve and vibrational spectrum that
significantly improves on... | 2206.10738v2 |
2022-07-06 | A comparison between the one- and two-step spin-orbit coupling approaches based on the ab initio Density Matrix Renormalization Group | The efficient and reliable treatment of both spin-orbit coupling (SOC) and
electron correlation is essential for understanding f-element chemistry. We
analyze two approaches to the problem, the one-step approach where both effects
are treated simultaneously, and the two-step state interaction approach. We
report an imp... | 2207.02435v2 |
2022-09-07 | Testing the Gallium Anomaly | We study the online detection by gallium capture of mono-energetic neutrinos
produced by a $^{51}$Cr radioactive source in a scintillation experiment. We
find that cerium-doped gadolinium aluminum gallium garnet (GAGG) is a suitable
scintillator which contains about 21% of gallium per weight and has a high mass
density... | 2209.02885v3 |
2022-08-16 | Arithmetic circuit tensor networks, multivariable function representation, and high-dimensional integration | Many computational problems can be formulated in terms of high-dimensional
functions. Simple representations of such functions and resulting computations
with them typically suffer from the "curse of dimensionality", an exponential
cost dependence on dimension. Tensor networks provide a way to represent
certain classes... | 2209.07410v1 |
2022-11-18 | Real time evolution of Anderson impurity models via tensor network influence functionals | In this work we present and analyze two tensor network-based influence
functional approaches for simulating the real-time dynamics of quantum impurity
models such as the Anderson model. Via comparison with recent numerically exact
simulations, we show that such methods accurately capture the long-time
non-equilibrium q... | 2211.10430v2 |
2022-11-25 | Asymmetric Faraday Effect in a Magnetophotonic Crystal | It is widely known that the magneto-optical Faraday effect is linear in
magnetization and therefore the Faraday angles for the states with opposite
magnetizations are of opposite sign but equal in modulus. Here we
experimentally study propagation of light through a one-dimensional all-garnet
magnetophotonic crystal to ... | 2211.14355v2 |
2022-12-18 | Exact relationships between the GW approximation and equation-of-motion coupled-cluster theories through the quasi-boson formalism | We describe the relationship between the GW approximation and various
equation-of-motion (EOM) coupled-cluster (CC) theories. We demonstrate the
exact equivalence of the G$_0$W$_0$ approximation and the propagator theory for
an electron-boson problem in a particular excitation basis. From there, we
establish equivalenc... | 2212.08982v1 |
2023-02-20 | Optimizing the magnon-phonon cooperativity in planar geometries | Optimizing the cooperativity between two distinct particles is an important
feature of quantum information processing. Of particular interest is the
coupling between spin and phonon, which allows for integrated long range
communication between gates operating at GHz frequency. Using local light
scattering, we show that... | 2302.09936v2 |
2023-05-04 | Quantum Enhanced Probes of Magnetic Circular Dichroism | Magneto-optical microscopies, including optical measurements of magnetic
circular dichroism, are increasingly ubiquitous tools for probing spin-orbit
coupling, charge-carrier g-factors, and chiral excitations in matter, but the
minimum detectable signal in classical magnetic circular dichroism measurements
is fundament... | 2305.02904v1 |
2023-06-07 | Simulating quantum circuit expectation values by Clifford perturbation theory | The classical simulation of quantum circuits is of central importance for
benchmarking near-term quantum devices. The fact that gates belonging to the
Clifford group can be simulated efficiently on classical computers has
motivated a range of methods that scale exponentially only in the number of
non-Clifford gates. He... | 2306.04797v2 |
2023-06-09 | Fermionic reduced density low-rank matrix completion, noise filtering, and measurement reduction in quantum simulations | Fermionic reduced density matrices summarize the key observables in fermionic
systems. In electronic systems, the two-particle reduced density matrix (2-RDM)
is sufficient to determine the energy and most physical observables of
interest. Here, we consider the possibility of using matrix completion to
reconstruct the t... | 2306.05640v1 |
2023-06-18 | Study of Ge Doped Garnet Type Li$_7$La$_3$Zr$_2$O$_{12}$ as Solid Electrolyte for Li-ion Battery Application | Li$_{7-4x}$Ge$_x$La$_3$Zr$_2$O$_{12}$ has been synthesized using the
conventional solid-state reaction method by substituting Germanium (Ge) at the
Li site, which increases the Li-ion vacancies and leads to an increase in
conductivity with $x$ varying from 0.05-0.20. The formation of cubic phase is
confirmed by using X... | 2306.10483v1 |
2023-06-28 | Ab initio quantum many-body description of superconducting trends in the cuprates | Using a systematic ab initio quantum many-body approach that goes beyond
low-energy models, we directly compute the superconducting pairing order of
several doped cuprate materials and structures. We find that we can correctly
capture two well-known trends: the pressure effect, where pairing order
increases with intra-... | 2306.16561v2 |
2023-08-07 | Adiabatic quantum imaginary time evolution | We introduce an adiabatic state preparation protocol which implements quantum
imaginary time evolution under the Hamiltonian of the system. Unlike the
original quantum imaginary time evolution algorithm, adiabatic quantum
imaginary time evolution does not require quantum state tomography during its
runtime, and unlike ... | 2308.03292v1 |
2023-08-09 | Fast and converged classical simulations of evidence for the utility of quantum computing before fault tolerance | A recent quantum simulation of observables of the kicked Ising model on 127
qubits implemented circuits that exceed the capabilities of exact classical
simulation. We show that several approximate classical methods, based on sparse
Pauli dynamics and tensor network algorithms, can simulate these observables
orders of m... | 2308.05077v3 |
2023-08-13 | Measurement of the non-linearity in the gamma-ray response of the GAGG:Ce inorganic scintillator | A characteristic of every inorganic scintillator crystal is its light yield,
i.e., the amount of emitted scintillation photons per unit of energy deposited
in the crystal. Light yield is known to be usually non-linear with energy,
which impacts the spectroscopic properties of the scintillator. Cerium-doped
gadolinium-a... | 2308.06759v1 |
2023-08-15 | Enhancement in Li-ion Conductivity through Co-doping of Ge and Ta in Garnet Li$_7$La$_3$Zr$_2$O$_{12}$ Solid Electrolyte | For being used as an electrolyte in All Solid State Batteries (ASSB), a solid
electrolyte must possess ionic conductivity comparable to that of conventional
liquid electrolytes. To achieve this conductivity range, the series
Li$_{6.8-y}$Ge$_{0.05}$La$_3$Zr$_{2-y}$Ta$_y$O$_{12}$ ($y = 0, 0.15, 0.25,
0.35, 0.45$) has bee... | 2308.07716v1 |
2023-10-05 | Block2: a comprehensive open source framework to develop and apply state-of-the-art DMRG algorithms in electronic structure and beyond | Block2 is an open source framework to implement and perform density matrix
renormalization group and matrix product state algorithms. Out-of-the-box it
supports the eigenstate, time-dependent, response, and finite-temperature
algorithms. In addition, it carries special optimizations for ab initio
electronic structure H... | 2310.03920v2 |
2023-11-23 | Invariable generation of certain branch groups | We investigate invariable generation among key examples of branch groups. In
particular, we prove that all generating sets of the torsion Grigorchuk groups,
of the branch Grigorchuk-Gupta-Sidki groups and of the torsion multi-EGS groups
(which are natural generalisations of the Grigorchuk-Gupta-Sidki groups) are
invari... | 2311.14022v1 |
2023-11-30 | AB-G$_0$W$_0$: A practical G$_0$W$_0$ method without frequency integration based on an auxiliary boson expansion | Common G$_0$W$_0$ implementations rely on numerical or analytical frequency
integration to determine the G$_0$W$_0$ self-energy, which results in a variety
of practical complications. Recently, we demonstrated an exact connection
between the G$_0$W$_0$ approximation and equation-of-motion (EOM) quantum
chemistry approa... | 2311.18304v1 |
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