There are five companies that I am aware of who manufacture high temperature superconducting products and do the R&D necessary to make this happen:
American superconductor (AMSC)
SuperPower (Home Page | SuperPower)
Superconductor Technologies Inc (STI - Superconductor Technologies, Inc.)
HTS-110 (Magnetic solutions utilising high temperature superconducting wire)
Can-Superconductors (CAN SUPERCONDUCTORS)
Additionally, it should be mentioned that high temperature superconductivity was discovered at IBM Zurich, though I don't think IBM research still does a lot of work in this area.
Good in what sense?
It's a good area in terms of its variety of unsolved problems. Usually the media only talks about high temperature superconductors, but these are not the only superconductors people study. In fact, there is a panoply of superconducting materials which challenge the 'old school' knowledge in textbooks.
It's also a good area to study in terms of where it lands on the spectrum of basic/applied physics and where it lands on the spectrum of public knowledge/ignorance. Regarding the former, the field of superconductivity straddles almost the full spectrum from very basic to ve
Good in what sense?
It's a good area in terms of its variety of unsolved problems. Usually the media only talks about high temperature superconductors, but these are not the only superconductors people study. In fact, there is a panoply of superconducting materials which challenge the 'old school' knowledge in textbooks.
It's also a good area to study in terms of where it lands on the spectrum of basic/applied physics and where it lands on the spectrum of public knowledge/ignorance. Regarding the former, the field of superconductivity straddles almost the full spectrum from very basic to very applied (applied is not necessarily the same thing as useful), so individual researchers choose a niche which suits their temperament. Regarding the latter, many non-scientists have heard of superconductivity or can understand why the concept is interesting, but the field is not so hyped (at least not right now in 2014) that researchers can be accused of misleading the public.
It is also a good area of research for giving people knowledge of solid state physics in general and novel materials in particular. After all, before a material becomes superconducting at low temperature, it has other properties (sometimes equally interesting) in the normal state, which need to be understood as a prerequisite to tackling superconductivity. With this background, researchers can pivot to new problems in solid state physics, if the winds of science funding blow that way, or pivot outside of academia if they need/want to.
Depending on the design of the MRI machine, the coils that carry the current that generate the very large magnetic fields are made of superconducting wire (probably niobium-titanium, which becomes superconducting below 9.4K clad in copper) and cooled below its superconducting transition temperature with liquid helium. Helium liquifies at 4.2 kelvin. And that is sufficient to keep the magnet coils in their superconducting state so they can carry the very high current needed without generating any heat due to the zero resistance of the superconducting coils.
None of that is trivial, of course, as
Depending on the design of the MRI machine, the coils that carry the current that generate the very large magnetic fields are made of superconducting wire (probably niobium-titanium, which becomes superconducting below 9.4K clad in copper) and cooled below its superconducting transition temperature with liquid helium. Helium liquifies at 4.2 kelvin. And that is sufficient to keep the magnet coils in their superconducting state so they can carry the very high current needed without generating any heat due to the zero resistance of the superconducting coils.
None of that is trivial, of course, as the magnet coils need to be surrounded by liquid helium, when needs thermal shielding and a vacuum space to prevent heat intrusion from the outside, etc. Hence the very large machine to produce the high magnetic field within the MRI tube.
MRI machines are one - big “atom smashers” like the Large Hadron Collider are another.
The main problem is that keeping these systems cold enough is difficult - so most of the really cool applications are a way off yet.
A superconductor is a material that can conduct electricity with zero resistance. This means when the conductors become superconductors below the critical temperature there will not be any loss of energy due to heat, sound, etc.
First of all, I humbly apologize as I am not sure what kind of characteristic you are referring to as I think that the word “characteristic” is a bit too generally. By implying that you mean the common features or qualities of superconducting materials may have, here are my opinions.
In my understanding, all superconducting materials share this same feature. All superconducting materials have not just small amount but absolutely zero electrical resistance when they are cooled to critical temperature, Tc. However, each materials have different Tc.
Another interesting characteristic of superconduc
First of all, I humbly apologize as I am not sure what kind of characteristic you are referring to as I think that the word “characteristic” is a bit too generally. By implying that you mean the common features or qualities of superconducting materials may have, here are my opinions.
In my understanding, all superconducting materials share this same feature. All superconducting materials have not just small amount but absolutely zero electrical resistance when they are cooled to critical temperature, Tc. However, each materials have different Tc.
Another interesting characteristic of superconducting materials are their magnetic field. While in the superconducting state, a superconducting material will tend to exclude and cancel all the magnetic fields. This phenomenon is known as the Meissner effect. However, based on my knowledge, superconducting material will be non-superconductive when the magnetic field strength intensifies beyond a critical level.
In another words, superconducting materials will lose their superconductivity no matter how you can chill them when they are exposed to magnetic field that is too powerful. Furthermore, the presence of magnetic field tends to lower the critical temperature of any superconducting material. This implies that the more magnetic field present, the colder you have to make the material before it will conduct with superconductivity.
That is why researchers have been putting a lot of efforts in developing “high-temperature” superconductors which can superconduct at warmer temperatures. Ideally, a superconductor should be able to be utilised in within the range of ambient temperatures, or at least within the range of inexpensive chilling equipment.
Cheers! Thank you.
This is the highest temperature at which superconductivity is achieved Superconductivity at 250 K in lanthanum hydride under high pressures. This is at high pressures. There are hundreds of research going on in this topic but high temperature and normal pressure superconductivity is still in not in workable phase.
Follwing aspects worth doing:
- Superconductivity at higher temperatures
- Cheaper materials or construction of system
- Superconductor Magnetic Energy Storage systems. (SMES)
SMES requires further research to make it easier to install and operate. Running costs need to be brought down.
Superconductors will have zero resistance to the electric current at low temperatures. Since space is mostly vaccum and cold(3 Kelvin) superconductors can be used.
But can be only used when the system or equipment is under the shade of a celestial body. Since most of the equipments we use in space are under the exposure of radiation from sun and other C bodies.
The space equipments generally use heat shields to prevent overheating and liquid helium to cool down the heat being dissipated.
Now if we use superconductors in space, when they are exposed to radiation of any sort, they'll dissipate more
Superconductors will have zero resistance to the electric current at low temperatures. Since space is mostly vaccum and cold(3 Kelvin) superconductors can be used.
But can be only used when the system or equipment is under the shade of a celestial body. Since most of the equipments we use in space are under the exposure of radiation from sun and other C bodies.
The space equipments generally use heat shields to prevent overheating and liquid helium to cool down the heat being dissipated.
Now if we use superconductors in space, when they are exposed to radiation of any sort, they'll dissipate more heat and use more liquid helium.
Once liquid helium reserve is depleted, the parts containing the superconductor will no longer operate leading to failure of functionality of that part or failure of whole equipment.
It is much more complicated. but this is the basic idea of why superconductors aren't being used in the space equipment.
Superconductivity is a property and superconductors are the things of which the property is. Like charge and electric field or magnet and magnetic field.
I don't know for sure, but I would look at Princeton, MIT, Caltech, Stanford, U Chicago, and the University of Illinois at Urbana-Champaign.
I think your question was “qbits” not “quits”.
This area requires a significant level of funding. So not knowing your personal credentials or research history I can only say that competition for research money in this area is more rather than less… so unless you are looking at a theory only paper I would say its pretty uphill for a new guy.
Te main unresolved issues are in the copper-oxide superconductors, such as the origin of superconductivity, the nature of the pseudogap, the origin of time-reveral symmetry breaking, etc.
It depends what you are trying to get as a beginner.
A general overview with very little mathematics: Amazon.com: Superconductivity: A Very Short Introduction (9780199540907): Stephen J. Blundell: Books
A comprehensive introduction with simplified formalism: Superconductivity, Superfluids, and Condensates (Oxford Master Series in Condensed Matter Physics): James F. Annett: 9780198507567: Amazon.com: Books
A very short introduction with some formalism: the superconductivity chapter in standard solid state physics textbooks such as Kittel (for undergrads) or Ashcroft&Mermin (for undergrads and grad
It depends what you are trying to get as a beginner.
A general overview with very little mathematics: Amazon.com: Superconductivity: A Very Short Introduction (9780199540907): Stephen J. Blundell: Books
A comprehensive introduction with simplified formalism: Superconductivity, Superfluids, and Condensates (Oxford Master Series in Condensed Matter Physics): James F. Annett: 9780198507567: Amazon.com: Books
A very short introduction with some formalism: the superconductivity chapter in standard solid state physics textbooks such as Kittel (for undergrads) or Ashcroft&Mermin (for undergrads and grad students)
Superconductors repell magnetic fields. This is achieved by surface currents. But real surface currents do not exist. They have some depth. This is dept is calked penetration dept. Of course, there is also no sharp boundary. So the depth is defined as the depth where the field is reduced by some factor. This is similar to the penetration depth of the skin effect for high frequency AC.
It allows for enormously greater electrical currents for the magnets without exorbitant power costs or the problems of concomitant heating.
Superconductivity is the ability of certain materials to conduct electric current with practically zero resistance. For a material to behave as a superconductor, low temperatures are required
It is an exciting time to be studying superconductors, because we are finding that this phenomenon emerges under various unexpected conditions. From the perspective of basic science it is important to study both high-Tc and low-Tc materials because the latter can also yield important insight into engineering more useful superconductors. Here are some popular recent research areas, in order of semi reverse chronological order.
- Topological superconductors. One of the most popular new research direction in the area of quantum materials in recent years has been topological insulators. These ar
It is an exciting time to be studying superconductors, because we are finding that this phenomenon emerges under various unexpected conditions. From the perspective of basic science it is important to study both high-Tc and low-Tc materials because the latter can also yield important insight into engineering more useful superconductors. Here are some popular recent research areas, in order of semi reverse chronological order.
- Topological superconductors. One of the most popular new research direction in the area of quantum materials in recent years has been topological insulators. These are materials which are insulating in the bulk, but have a non-trivial topologically protected metallic surface state. Research in topological superconductivity attempts to introduce superconductivity into this problem, either via proximity effect to a confirmed superconductor or by making the bulk superconducting. A topological superconductor is thought to be an avenue for observing a Majorana Fermion, a particle (or quasiparticle in the context of a condensed matter system) which is its own antiparticle. As far as I know, there is no widely accepted topological superconductor (many proposals and claims though). An introduction can be found here: [1206.1736] Introduction to topological superconductivity and Majorana fermions
- Trying to make Graphene superconduct. No luck yet, but graphitic superconductors do exist, and an example is CaC6 (Ca atoms intercalated between the layers of graphite).
- Lanthanum-aluminate/Strontium-titanate (LAO/STO) interface superconductivity (Lanthanum aluminate-strontium titanate interface). Both LAO and STO are insualtors, but when they are brought into very close contact via epitaxial thin film growth, a metallic region forms at the interface and becomes superconducting when cooled sufficiently. The mechanism of superconductivity in this structure is still debated. This is an exciting topic because in the past, people have mainly studied how to affect superconductivity by changing the chemistry or crystal structure of a bulk material. In the LAO/STO system, the interface is the key player. Understanding this system may provide insight on how to produce high temperature superconductivity by picking the two proper materials to produce the heterostructure.
- FeSe monolayers. FeSe can be grown as a bulk crystal and in that case it has a Tc of 10K. However, when a one-unit-cell-thick film is grown on strontium-titanate (substrate is important), the Tc is much higher, 40-70K (!!!)(exact number is debated because it is hard to measure Tc unambiguously in a monolayer). The anomalously large Tc only happens in one-unit-cell-thick films; 2 unit cells has a lower Tc. The mechanism of this enhancement is also debated, but most proposals implicate coupling to physics (perhaps atomic vibrations, to be more specific) in the substrate. Both this research area and the one above implicate the emerging importance of thin-film growth to modern superconductivity research.
- Fe-based superconductors. In 2008, a new family of 'high temperature' superconductors was discovered, the so-called 'iron-pnictides' (Iron-based superconductor). These materials have Tc up to ~60K, and the mechanism is still debated. Prior to 2008, many different types of superconductors were known, but none of them had high Tc. The iron pnictides showed that high-temperature superconductivity (here, 'high Tc' is defined as >40K because that is the rough upper limit of BCS theory) is a more generic materials phenomenon, and there is hope for engineering other high temperature superconductors.
- Superconductivity+charge density wave (CDW) order system. This is a problem that has been studied in the past, but is being revisited because of suggestions that CDW may coexist with and compete with superconductivity in the cuprate high temperature superconductors. Materials in this class are thought to be cute model systems (i.e. we understand the physics and we just want to measure how an 'ideal' system behaves), but often non-trivial things are discovered when people investigate closely. Examples of popular materials are NbSe2 (2D) and Ba1−xKxBiO3 (3D).
- Cuprate high temperature superconductors (High-temperature superconductivity). This is an older topic (since 1986), but still an area of very active research because these materials boast the highest transition temperatures (up to 164K) and the mechanism of high temperature superconductivity is still debated. On the experimental side, this difficult problem is becoming more tractable because the samples are becoming increasingly high-quality and the experimental tools are becoming more sophisticated. On the theory side, see my previous answer What are the latest theories in high temperature superconductivity?. Many people who study cuprates also study other superconductors discussed above, and the breadth of information gained from this approach is promising for uncovering the mechanism of high temperature superconductivity.
- Heavy Fermion superconductors. This is a topic which is even older than cuprates, but it is becoming more popular these days because people are appreciating the insights that the low-Tc heavy Fermions can provide to other types of superconductors. The heavy Fermion superconductors get their name because at temperatures above Tc, electrons in these materials have effective masses up to 1000 times the free electron mass (almost at heavy at a proton!) (Wikipedia article: Heavy fermion). Such a huge effective mass indicates that electrons are strongly interacting with something, and magnetic degrees of freedom are the likely culprit in this case. A predictive understanding of strong correlation in condensed matter system still eludes physicists. Modern experimental tools are making an impact on the field of heavy Fermions as well.
Ok, let's get focused. Undergraduate means undergraduate where you are exposed to many different types of educational offerings and classes. First, you have to walk before you can run so typically the first two years of your undergraduate program are filled with General Education Type Courses to provide you with general knowledge and ultimately to focus you on the last two years of college where you will select a a major. No college of university, at least to my knowledge offers "superconductivity" as a major area of study; but, they do offer numerous science majors that will prepare you to st
Ok, let's get focused. Undergraduate means undergraduate where you are exposed to many different types of educational offerings and classes. First, you have to walk before you can run so typically the first two years of your undergraduate program are filled with General Education Type Courses to provide you with general knowledge and ultimately to focus you on the last two years of college where you will select a a major. No college of university, at least to my knowledge offers "superconductivity" as a major area of study; but, they do offer numerous science majors that will prepare you to study "superconductivity" should you decide to attend Graduate School. The one that I would focus on, if my interest is in superconductivity would be Physics; and, believe me Physics, even in an undergraduate program is "no walk in the park." So, before you decide to jump right into a graduate program, I strongly suggest you first sample the many different courses and majors, science or otherwise, undergraduate institutions offer before committing to one major or another. Indeed, changing majors is the most common reason why students don't graduate from college in four years. Regards, Dr. Rick (Steiner), author of Retirement: Different by Design
It would be so much more helpful if you would elaborate on what you mean by "destroy" superconductivity. If superconductivity is what is happening across any conducting medium, it means the resistance of that medium is extremely low. Current flowing through a superconductor then will have a very low voltage drop across the length of the conductor. That said, a measure of the superconductivity could be made by measuring the voltage drop across the conductor. As this measured voltage goes up, the super conductivity is going down. However, the voltage developed across the conductor is not acting
It would be so much more helpful if you would elaborate on what you mean by "destroy" superconductivity. If superconductivity is what is happening across any conducting medium, it means the resistance of that medium is extremely low. Current flowing through a superconductor then will have a very low voltage drop across the length of the conductor. That said, a measure of the superconductivity could be made by measuring the voltage drop across the conductor. As this measured voltage goes up, the super conductivity is going down. However, the voltage developed across the conductor is not acting to destroy the super conductivity. Loss of super conductivity is affected most by heat.
Hope this helps.
The original ‘test’ for superconductivity was done by Professor Heike Kamerlingh Onnes in 1911 as he was measuring the decreasing resistivity of extremely pure mercury as he cooled it to record low temperatures. He found that the resistance dropped abruptly to a value too low for his cutting edge instruments to measure. He was able to verify that the resistance was zero by starting a current flowing in a loop that would continue to flow without and external voltage being applied.
Other tests include the Meissner–Ochsenfeld effect Effect which involve the exclusion of magnetic fields from the ma
The original ‘test’ for superconductivity was done by Professor Heike Kamerlingh Onnes in 1911 as he was measuring the decreasing resistivity of extremely pure mercury as he cooled it to record low temperatures. He found that the resistance dropped abruptly to a value too low for his cutting edge instruments to measure. He was able to verify that the resistance was zero by starting a current flowing in a loop that would continue to flow without and external voltage being applied.
Other tests include the Meissner–Ochsenfeld effect Effect which involve the exclusion of magnetic fields from the material.
When I started in superconductors in 1988 THE book to read was ‘Superconducting Magnets’ by Martin N. Wilson, Oxford Science Publications. Used and new copies can be found on the Internet.
Originally published in 1983 before the discovery of so-called ‘high temperature’ superconducting materials (HTC), it only deals with metallic or ‘low temperature’ superconductors (LTC) but does it extremely well. My copy is falling apart: I used it extensively during my nearly fifteen years of building energy storage magnets in Madison, Wisconsin.
I haven’t watched the S/C industry or tech area very closely o
When I started in superconductors in 1988 THE book to read was ‘Superconducting Magnets’ by Martin N. Wilson, Oxford Science Publications. Used and new copies can be found on the Internet.
Originally published in 1983 before the discovery of so-called ‘high temperature’ superconducting materials (HTC), it only deals with metallic or ‘low temperature’ superconductors (LTC) but does it extremely well. My copy is falling apart: I used it extensively during my nearly fifteen years of building energy storage magnets in Madison, Wisconsin.
I haven’t watched the S/C industry or tech area very closely over the past decade but I am not aware of any commercially profitable application of HTC materials while LTC materials continue to be used in MRI magnets, high energy physics (LHC and similar units) and, more recently, in the ITER fusion experiment being constructed in France. Manufacturers of LTC conductors generally stay in business and often make a profit (which is one of the objectives of being in business).
Mr. Gerig’s advice is well taken - if you want to keep up with the field you need to plow through a mass of good/indifferent/bad research papers and sort out the gold from the dross. However, to do this, you need a good grounding in the phenomena of superconductivity itself as well as cryogenics, power and instrumentation electronics and the engineering of things built at room temperature yet operated at cryogenic temperatures.
Despite being dated, Mr. Wilson’s book is a great leg up.
I always viewed my job as playing huge church organ - I had many keyboards, stops, pedals and other controls to produce an end product - a good magnet. It was the greatest adventure of my life (well, besides climbing mountains and raising kids with my wife).
Best of luck - keep learning and don’t give up. The prize goes to the most persistent (as in persistent current).
wb
It was discovered by Dutch physicistHeike Kamerlingh Onnes on April 8, 1911, in Leiden.
Experimentally it is observed that the resistance of some substances like tin,lead,etc. decreases tremendously with the decrease in temperature and becomes almost zero in a very low temperature range(i.e., near absolute zero). The substances under this condition are called “SUPERCONDUCTORS”.
Once the current is set up in the superconductor, the current persists for a very long time without applying any voltage across it i.e, the resistance of a superconductor is almost zero(or its conductance is infinite).
A S
It was discovered by Dutch physicistHeike Kamerlingh Onnes on April 8, 1911, in Leiden.
Experimentally it is observed that the resistance of some substances like tin,lead,etc. decreases tremendously with the decrease in temperature and becomes almost zero in a very low temperature range(i.e., near absolute zero). The substances under this condition are called “SUPERCONDUCTORS”.
Once the current is set up in the superconductor, the current persists for a very long time without applying any voltage across it i.e, the resistance of a superconductor is almost zero(or its conductance is infinite).
A SUPERCONDUCTOR IS A SUBSTANCE OF ZERO RESISTANCE (or infinite conductance) AT A VERY LOW TEMPERATURE.
EXAMPLES: Mercury below 4.2K , lead below 7.25K and niobium below 9.2K are the superconductors.
The superconductors are not in on use since it is very difficult to achieve such a low temperature. However they can be very useful if it is possible to obtain them at room temperature. The size of computers would then be reduced to a few centimetres and the power lines could then be made as thin as a single wire.
I have provided some extra information too. Hope this helps you.