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1820 1821 1822 1823 1824 1825 1826 1827 1828 1829 1830 1831 1832 1833 1834 1835 1836 1837 1838 1839 1840 1841 1842 1843 1844 1845 1846 1847 1848 1849 1850 1851 1852 1853 1854 1855 1856 1857 1858 1859 1860 1861 1862 1863 1864 1865 1866 1867 1868 1869 1870 1871 1872 1873 1874 1875 | align:start position:0% in this demonstration I'm going to show align:start position:0% in this demonstration I'm going to show align:start position:0% in this demonstration I'm going to show you how to construct 2d brilliant zones align:start position:0% you how to construct 2d brilliant zones align:start position:0% you how to construct 2d brilliant zones and hopefully achieve a better align:start position:0% and hopefully achieve a better align:start position:0% and hopefully achieve a better understanding them and what they are so align:start position:0% understanding them and what they are so align:start position:0% understanding them and what they are so a brilliant zone is an important concept align:start position:0% a brilliant zone is an important concept align:start position:0% a brilliant zone is an important concept in material science and solid-state align:start position:0% in material science and solid-state align:start position:0% in material science and solid-state physics align:start position:0% physics align:start position:0% physics alike because it is used to describe the align:start position:0% alike because it is used to describe the align:start position:0% alike because it is used to describe the behavior of an electron in a perfect align:start position:0% behavior of an electron in a perfect align:start position:0% behavior of an electron in a perfect crystal system so what is a brilliant align:start position:0% crystal system so what is a brilliant align:start position:0% crystal system so what is a brilliant zone the Brillion zone is a particular align:start position:0% zone the Brillion zone is a particular align:start position:0% zone the Brillion zone is a particular choice of the unit cell of the align:start position:0% choice of the unit cell of the align:start position:0% choice of the unit cell of the reciprocal lattice is defined as the align:start position:0% reciprocal lattice is defined as the align:start position:0% reciprocal lattice is defined as the riegner Seitz cell of the reciprocal align:start position:0% riegner Seitz cell of the reciprocal align:start position:0% riegner Seitz cell of the reciprocal lattice it is constructed as the set of align:start position:0% lattice it is constructed as the set of align:start position:0% lattice it is constructed as the set of points and closed by the Bragg planes align:start position:0% points and closed by the Bragg planes align:start position:0% points and closed by the Bragg planes the planes perpendicular to a connection align:start position:0% the planes perpendicular to a connection align:start position:0% the planes perpendicular to a connection line from the origin of to each lattice align:start position:0% line from the origin of to each lattice align:start position:0% line from the origin of to each lattice point passing through the midpoint align:start position:0% point passing through the midpoint align:start position:0% point passing through the midpoint alternatively it is defined as the set align:start position:0% alternatively it is defined as the set align:start position:0% alternatively it is defined as the set of points closer to the origin than to align:start position:0% of points closer to the origin than to align:start position:0% of points closer to the origin than to any other reciprocal lattice point the align:start position:0% any other reciprocal lattice point the align:start position:0% any other reciprocal lattice point the whole reciprocal space may be covered align:start position:0% whole reciprocal space may be covered align:start position:0% whole reciprocal space may be covered without overlap with copies of such align:start position:0% without overlap with copies of such align:start position:0% without overlap with copies of such brilliant zone okay so that was a rather align:start position:0% brilliant zone okay so that was a rather align:start position:0% brilliant zone okay so that was a rather convoluted definition let's do it again align:start position:0% convoluted definition let's do it again align:start position:0% convoluted definition let's do it again let's brush up and be sure that we align:start position:0% let's brush up and be sure that we align:start position:0% let's brush up and be sure that we understand this definition we're going align:start position:0% understand this definition we're going align:start position:0% understand this definition we're going to define her the reciprocal space the align:start position:0% to define her the reciprocal space the align:start position:0% to define her the reciprocal space the Bragg planes as well but it's fine both align:start position:0% Bragg planes as well but it's fine both align:start position:0% Bragg planes as well but it's fine both of these will also do a quick revision align:start position:0% of these will also do a quick revision align:start position:0% of these will also do a quick revision of what is there a record lattice so align:start position:0% of what is there a record lattice so align:start position:0% of what is there a record lattice so that we can go from there to the align:start position:0% that we can go from there to the align:start position:0% that we can go from there to the reciprocal lattice the microscopic align:start position:0% reciprocal lattice the microscopic align:start position:0% reciprocal lattice the microscopic perfect crystal is formed by adding align:start position:0% perfect crystal is formed by adding align:start position:0% perfect crystal is formed by adding identical building blocks so to say unit align:start position:0% identical building blocks so to say unit align:start position:0% identical building blocks so to say unit cells consisting of atoms and groups of align:start position:0% cells consisting of atoms and groups of align:start position:0% cells consisting of atoms and groups of atoms a unit cell is the smallest align:start position:0% atoms a unit cell is the smallest align:start position:0% atoms a unit cell is the smallest component of a crystal that one stacked align:start position:0% component of a crystal that one stacked align:start position:0% component of a crystal that one stacked together with pure translational align:start position:0% together with pure translational align:start position:0% together with pure translational repetition reproducing the whole crystal align:start position:0% repetition reproducing the whole crystal align:start position:0% repetition reproducing the whole crystal which essentially means that you can align:start position:0% which essentially means that you can align:start position:0% which essentially means that you can take the same thing over and over and align:start position:0% take the same thing over and over and align:start position:0% take the same thing over and over and over again and get the whole system done align:start position:0% over again and get the whole system done align:start position:0% over again and get the whole system done so and the groups of atoms these unit align:start position:0% so and the groups of atoms these unit align:start position:0% so and the groups of atoms these unit cells that form the microscopic crystal align:start position:0% cells that form the microscopic crystal align:start position:0% cells that form the microscopic crystal but infinite repetition is called the align:start position:0% but infinite repetition is called the align:start position:0% but infinite repetition is called the basis okay that seems quite clear and align:start position:0% basis okay that seems quite clear and align:start position:0% basis okay that seems quite clear and the basis is formed in such a way that align:start position:0% the basis is formed in such a way that align:start position:0% the basis is formed in such a way that it forms the lattice more commonly known align:start position:0% it forms the lattice more commonly known align:start position:0% it forms the lattice more commonly known as the Rivervale at every point of a align:start position:0% as the Rivervale at every point of a align:start position:0% as the Rivervale at every point of a breve lattice is equivalent to every align:start position:0% breve lattice is equivalent to every align:start position:0% breve lattice is equivalent to every other point which means that the align:start position:0% other point which means that the align:start position:0% other point which means that the arrangement atoms and the crystal is the align:start position:0% arrangement atoms and the crystal is the align:start position:0% arrangement atoms and the crystal is the same when viewed from different lattice align:start position:0% same when viewed from different lattice align:start position:0% same when viewed from different lattice points okay that also seems align:start position:0% points okay that also seems align:start position:0% points okay that also seems understandable and you should probably align:start position:0% understandable and you should probably align:start position:0% understandable and you should probably know that by now so any fundamental align:start position:0% know that by now so any fundamental align:start position:0% know that by now so any fundamental lattice must be definable by three align:start position:0% lattice must be definable by three align:start position:0% lattice must be definable by three primitive translational vectors a1 a2 align:start position:0% primitive translational vectors a1 a2 align:start position:0% primitive translational vectors a1 a2 and a3 the combination of these vectors align:start position:0% and a3 the combination of these vectors align:start position:0% and a3 the combination of these vectors is using to find the crystal align:start position:0% is using to find the crystal align:start position:0% is using to find the crystal translational vector R such that R is align:start position:0% translational vector R such that R is align:start position:0% translational vector R such that R is equal to a 1 and 1 plus a 2 and 2 plus a align:start position:0% equal to a 1 and 1 plus a 2 and 2 plus a align:start position:0% equal to a 1 and 1 plus a 2 and 2 plus a 3 and 3 where n are just arbitrary align:start position:0% 3 and 3 where n are just arbitrary align:start position:0% 3 and 3 where n are just arbitrary integers to show that Mark would show align:start position:0% integers to show that Mark would show align:start position:0% integers to show that Mark would show the size of our lattice so when we the align:start position:0% the size of our lattice so when we the align:start position:0% the size of our lattice so when we the crystal lattice is repeated an infinite align:start position:0% crystal lattice is repeated an infinite align:start position:0% crystal lattice is repeated an infinite amount of times to create the perfect align:start position:0% amount of times to create the perfect align:start position:0% amount of times to create the perfect crystal structure and each of those align:start position:0% crystal structure and each of those align:start position:0% crystal structure and each of those lattices are translationally symmetric align:start position:0% lattices are translationally symmetric align:start position:0% lattices are translationally symmetric and the way I'll look at is is that one align:start position:0% and the way I'll look at is is that one align:start position:0% and the way I'll look at is is that one cannot tell their positional in crystal align:start position:0% cannot tell their positional in crystal align:start position:0% cannot tell their positional in crystal structure because every lattice looks align:start position:0% structure because every lattice looks align:start position:0% structure because every lattice looks this ok so now okay so that seems to align:start position:0% this ok so now okay so that seems to align:start position:0% this ok so now okay so that seems to make sense so now let's go through align:start position:0% make sense so now let's go through align:start position:0% make sense so now let's go through reciprocal space okay so every lattice align:start position:0% reciprocal space okay so every lattice align:start position:0% reciprocal space okay so every lattice has a reciprocal lattice associated align:start position:0% has a reciprocal lattice associated align:start position:0% has a reciprocal lattice associated through in crystallography terms the align:start position:0% through in crystallography terms the align:start position:0% through in crystallography terms the reciprocal lattices of the diffraction align:start position:0% reciprocal lattices of the diffraction align:start position:0% reciprocal lattices of the diffraction prior of a crystal or in quantum align:start position:0% prior of a crystal or in quantum align:start position:0% prior of a crystal or in quantum mechanics it's described this k space align:start position:0% mechanics it's described this k space align:start position:0% mechanics it's described this k space with K being 4k wave vectors in 3d align:start position:0% with K being 4k wave vectors in 3d align:start position:0% with K being 4k wave vectors in 3d lattice the vectors would be v1 v2 and align:start position:0% lattice the vectors would be v1 v2 and align:start position:0% lattice the vectors would be v1 v2 and v3 and they can be denoted it as well align:start position:0% v3 and they can be denoted it as well align:start position:0% v3 and they can be denoted it as well look at it just b1 b1 is equals to 2 pi align:start position:0% look at it just b1 b1 is equals to 2 pi align:start position:0% look at it just b1 b1 is equals to 2 pi times the cross product of the vectors align:start position:0% times the cross product of the vectors align:start position:0% times the cross product of the vectors a2 and a3 from our direct lattice align:start position:0% a2 and a3 from our direct lattice align:start position:0% a2 and a3 from our direct lattice divided by the triple cross scalar align:start position:0% divided by the triple cross scalar align:start position:0% divided by the triple cross scalar product of a 1 a 2 and a 3 in which case align:start position:0% product of a 1 a 2 and a 3 in which case align:start position:0% product of a 1 a 2 and a 3 in which case this cross product of a 2 and a 3 is the align:start position:0% this cross product of a 2 and a 3 is the align:start position:0% this cross product of a 2 and a 3 is the area of our vector of our two vectors in align:start position:0% area of our vector of our two vectors in align:start position:0% area of our vector of our two vectors in the triple scalar product is the volume align:start position:0% the triple scalar product is the volume align:start position:0% the triple scalar product is the volume of our system by simplifying it we can align:start position:0% of our system by simplifying it we can align:start position:0% of our system by simplifying it we can just get 2 pi over the height of our align:start position:0% just get 2 pi over the height of our align:start position:0% just get 2 pi over the height of our unit cell or we can put it in this way align:start position:0% unit cell or we can put it in this way align:start position:0% unit cell or we can put it in this way the larger our direct lattice gets the align:start position:0% the larger our direct lattice gets the align:start position:0% the larger our direct lattice gets the smaller and core person or reciprocal align:start position:0% smaller and core person or reciprocal align:start position:0% smaller and core person or reciprocal lattice becomes another observation that align:start position:0% lattice becomes another observation that align:start position:0% lattice becomes another observation that could actually be made by the reciprocal align:start position:0% could actually be made by the reciprocal align:start position:0% could actually be made by the reciprocal lattices that the reciprocal lattice of align:start position:0% lattices that the reciprocal lattice of align:start position:0% lattices that the reciprocal lattice of the reciprocal lattice is the direct align:start position:0% the reciprocal lattice is the direct align:start position:0% the reciprocal lattice is the direct lattice bit okay for simplicity's sake align:start position:0% lattice bit okay for simplicity's sake align:start position:0% lattice bit okay for simplicity's sake let's look at a transformation from 2d align:start position:0% let's look at a transformation from 2d align:start position:0% let's look at a transformation from 2d lattice to a reciprocal lattice okay so align:start position:0% lattice to a reciprocal lattice okay so align:start position:0% lattice to a reciprocal lattice okay so we have a visualization here where we align:start position:0% we have a visualization here where we align:start position:0% we have a visualization here where we can change align:start position:0% can change align:start position:0% can change the length of our X vector indirect align:start position:0% the length of our X vector indirect align:start position:0% the length of our X vector indirect space and the length of our vibrator align:start position:0% space and the length of our vibrator align:start position:0% space and the length of our vibrator indirect space and we can change whether align:start position:0% indirect space and we can change whether align:start position:0% indirect space and we can change whether or not we're seeing this as a direct align:start position:0% or not we're seeing this as a direct align:start position:0% or not we're seeing this as a direct lattice or by pressing this button as a align:start position:0% lattice or by pressing this button as a align:start position:0% lattice or by pressing this button as a reciprocal lattice so as we can see but align:start position:0% reciprocal lattice so as we can see but align:start position:0% reciprocal lattice so as we can see but increasing the length of our direct align:start position:0% increasing the length of our direct align:start position:0% increasing the length of our direct direct vector we change the sizes of our align:start position:0% direct vector we change the sizes of our align:start position:0% direct vector we change the sizes of our reciprocal lattice vectors and the other align:start position:0% reciprocal lattice vectors and the other align:start position:0% reciprocal lattice vectors and the other way around align:start position:0% align:start position:0% okay so now we had a definition of the align:start position:0% okay so now we had a definition of the align:start position:0% okay so now we had a definition of the reciprocal space in the rect space let's align:start position:0% reciprocal space in the rect space let's align:start position:0% reciprocal space in the rect space let's go back to our definition so the first align:start position:0% go back to our definition so the first align:start position:0% go back to our definition so the first brilliant zone can be defined as a set align:start position:0% brilliant zone can be defined as a set align:start position:0% brilliant zone can be defined as a set of points in reciprocal space that can align:start position:0% of points in reciprocal space that can align:start position:0% of points in reciprocal space that can be reached from a specific point of align:start position:0% be reached from a specific point of align:start position:0% be reached from a specific point of origin without crossing any breakpoints align:start position:0% origin without crossing any breakpoints align:start position:0% origin without crossing any breakpoints came so what our Bragg planes a Bragg align:start position:0% came so what our Bragg planes a Bragg align:start position:0% came so what our Bragg planes a Bragg plane or in this case a Bragg line is a align:start position:0% plane or in this case a Bragg line is a align:start position:0% plane or in this case a Bragg line is a Bragg line with perpendicular bisector align:start position:0% Bragg line with perpendicular bisector align:start position:0% Bragg line with perpendicular bisector reciprocal lattice vector a vector which align:start position:0% reciprocal lattice vector a vector which align:start position:0% reciprocal lattice vector a vector which connects two lattice points and the align:start position:0% connects two lattice points and the align:start position:0% connects two lattice points and the closest Bragg planes are essentially align:start position:0% closest Bragg planes are essentially align:start position:0% closest Bragg planes are essentially accosting the Brillion zone now can show align:start position:0% accosting the Brillion zone now can show align:start position:0% accosting the Brillion zone now can show that the Bragg planes for the closest align:start position:0% that the Bragg planes for the closest align:start position:0% that the Bragg planes for the closest neighbors with this being our original align:start position:0% neighbors with this being our original align:start position:0% neighbors with this being our original lattice point these are the four closest align:start position:0% lattice point these are the four closest align:start position:0% lattice point these are the four closest neighbors in a simple I'd say cubic but align:start position:0% neighbors in a simple I'd say cubic but align:start position:0% neighbors in a simple I'd say cubic but it's actually just the square lattice align:start position:0% it's actually just the square lattice align:start position:0% it's actually just the square lattice because it's in 2d and if we add the align:start position:0% because it's in 2d and if we add the align:start position:0% because it's in 2d and if we add the second large vectors before the second align:start position:0% second large vectors before the second align:start position:0% second large vectors before the second closest neighbors you can see these ones align:start position:0% closest neighbors you can see these ones align:start position:0% closest neighbors you can see these ones and essentially conveys the same align:start position:0% and essentially conveys the same align:start position:0% and essentially conveys the same information when we go to a higher order align:start position:0% information when we go to a higher order align:start position:0% information when we go to a higher order of closest neighbors we can see that the align:start position:0% of closest neighbors we can see that the align:start position:0% of closest neighbors we can see that the system gets a lot more complex okay so align:start position:0% system gets a lot more complex okay so align:start position:0% system gets a lot more complex okay so now we've seen what our back planes can align:start position:0% now we've seen what our back planes can align:start position:0% now we've seen what our back planes can go towards brilliant zones so this is align:start position:0% go towards brilliant zones so this is align:start position:0% go towards brilliant zones so this is the first brilliant result it is what it align:start position:0% the first brilliant result it is what it align:start position:0% the first brilliant result it is what it seems it is as you can imagine the Bragg align:start position:0% seems it is as you can imagine the Bragg align:start position:0% seems it is as you can imagine the Bragg planes just go here and the brilliant align:start position:0% planes just go here and the brilliant align:start position:0% planes just go here and the brilliant zone shows us the area in reciprocal align:start position:0% zone shows us the area in reciprocal align:start position:0% zone shows us the area in reciprocal space that is closer to our lattice align:start position:0% space that is closer to our lattice align:start position:0% space that is closer to our lattice point than any other lattice point which align:start position:0% point than any other lattice point which align:start position:0% point than any other lattice point which are essentially the Bragg planes as well align:start position:0% are essentially the Bragg planes as well align:start position:0% are essentially the Bragg planes as well as we can see if our reciprocal lattice align:start position:0% as we can see if our reciprocal lattice align:start position:0% as we can see if our reciprocal lattice origin point isn't here this the square align:start position:0% origin point isn't here this the square align:start position:0% origin point isn't here this the square is closer to this point than to any align:start position:0% is closer to this point than to any align:start position:0% is closer to this point than to any other point and after these lines it align:start position:0% other point and after these lines it align:start position:0% other point and after these lines it gets the other way around align:start position:0% gets the other way around align:start position:0% gets the other way around so we can move on forward to a higher align:start position:0% so we can move on forward to a higher align:start position:0% so we can move on forward to a higher order of brilliant zones align:start position:0% align:start position:0% this is the Brillion zone for the second align:start position:0% this is the Brillion zone for the second align:start position:0% this is the Brillion zone for the second closest neighbor as you can see it it is align:start position:0% closest neighbor as you can see it it is align:start position:0% closest neighbor as you can see it it is rather similar it just takes the second align:start position:0% rather similar it just takes the second align:start position:0% rather similar it just takes the second closest neighbors and essentially draws align:start position:0% closest neighbors and essentially draws align:start position:0% closest neighbors and essentially draws another square it but it's a bit tilted align:start position:0% another square it but it's a bit tilted align:start position:0% another square it but it's a bit tilted to this okay so now let's look at the align:start position:0% to this okay so now let's look at the align:start position:0% to this okay so now let's look at the third one for the third brilliant zone align:start position:0% third one for the third brilliant zone align:start position:0% third one for the third brilliant zone that gets a bit more complex because if align:start position:0% that gets a bit more complex because if align:start position:0% that gets a bit more complex because if we scroll a bit backwards we can see align:start position:0% we scroll a bit backwards we can see align:start position:0% we scroll a bit backwards we can see that the third bread the breakfast for align:start position:0% that the third bread the breakfast for align:start position:0% that the third bread the breakfast for the thirtieth closest neighbors are align:start position:0% the thirtieth closest neighbors are align:start position:0% the thirtieth closest neighbors are these ones so we might think that this align:start position:0% these ones so we might think that this align:start position:0% these ones so we might think that this whole thing would be that brilliant the align:start position:0% whole thing would be that brilliant the align:start position:0% whole thing would be that brilliant the third brilliant look but it's actually align:start position:0% third brilliant look but it's actually align:start position:0% third brilliant look but it's actually not because with every next system it align:start position:0% not because with every next system it align:start position:0% not because with every next system it gets a bit more complex and it's align:start position:0% gets a bit more complex and it's align:start position:0% gets a bit more complex and it's actually taking account both the third align:start position:0% actually taking account both the third align:start position:0% actually taking account both the third right planes and the first ones okay so align:start position:0% right planes and the first ones okay so align:start position:0% right planes and the first ones okay so now let's do another thing let's turn align:start position:0% now let's do another thing let's turn align:start position:0% now let's do another thing let's turn off on that we can see all the Bragg align:start position:0% off on that we can see all the Bragg align:start position:0% off on that we can see all the Bragg planes and turn up another notch okay so align:start position:0% planes and turn up another notch okay so align:start position:0% planes and turn up another notch okay so here we can see that the fourth Brillion align:start position:0% here we can see that the fourth Brillion align:start position:0% here we can see that the fourth Brillion zone gets a lot more complex now we can align:start position:0% zone gets a lot more complex now we can align:start position:0% zone gets a lot more complex now we can see all the Bragg planes for the quite align:start position:0% see all the Bragg planes for the quite align:start position:0% see all the Bragg planes for the quite for the closest neighbors and these align:start position:0% for the closest neighbors and these align:start position:0% for the closest neighbors and these lines could get quite difficult to align:start position:0% lines could get quite difficult to align:start position:0% lines could get quite difficult to understand by drawing themselves but we align:start position:0% understand by drawing themselves but we align:start position:0% understand by drawing themselves but we can help ourselves out with this align:start position:0% can help ourselves out with this align:start position:0% can help ourselves out with this visualization so yeah we can see that align:start position:0% visualization so yeah we can see that align:start position:0% visualization so yeah we can see that they start to interact with each other align:start position:0% they start to interact with each other align:start position:0% they start to interact with each other and thus make a more difficult structure align:start position:0% and thus make a more difficult structure align:start position:0% and thus make a more difficult structure and if we go to the fifth one and see align:start position:0% and if we go to the fifth one and see align:start position:0% and if we go to the fifth one and see show that we can see all the brilliant align:start position:0% show that we can see all the brilliant align:start position:0% show that we can see all the brilliant zones okay so here we can see that it align:start position:0% zones okay so here we can see that it align:start position:0% zones okay so here we can see that it gets becomes quite a nice drawing if we align:start position:0% gets becomes quite a nice drawing if we align:start position:0% gets becomes quite a nice drawing if we were to keep adding them let's just it align:start position:0% were to keep adding them let's just it align:start position:0% were to keep adding them let's just it let's head to the ninth one okay so see align:start position:0% let's head to the ninth one okay so see align:start position:0% let's head to the ninth one okay so see here we can see a high order brilliant align:start position:0% here we can see a high order brilliant align:start position:0% here we can see a high order brilliant zones and it actually looked kind of align:start position:0% zones and it actually looked kind of align:start position:0% zones and it actually looked kind of nice which is also interesting because align:start position:0% nice which is also interesting because align:start position:0% nice which is also interesting because it's also an art form drawing high align:start position:0% it's also an art form drawing high align:start position:0% it's also an art form drawing high drawing high order billion zones align:start position:0% drawing high order billion zones align:start position:0% drawing high order billion zones the higher you go the more complex and align:start position:0% the higher you go the more complex and align:start position:0% the higher you go the more complex and more discrete the system gets in align:start position:0% more discrete the system gets in align:start position:0% more discrete the system gets in essentially it looks nicer okay so after align:start position:0% essentially it looks nicer okay so after align:start position:0% essentially it looks nicer okay so after looking at this we can get a short align:start position:0% looking at this we can get a short align:start position:0% looking at this we can get a short definition of how to construct to the align:start position:0% definition of how to construct to the align:start position:0% definition of how to construct to the brilliant zones so enth brilliant zone align:start position:0% brilliant zones so enth brilliant zone align:start position:0% brilliant zones so enth brilliant zone can be defined as the area or volume if align:start position:0% can be defined as the area or volume if align:start position:0% can be defined as the area or volume if we look in 3d in reciprocal space that align:start position:0% we look in 3d in reciprocal space that align:start position:0% we look in 3d in reciprocal space that can be reached from the origin but align:start position:0% can be reached from the origin but align:start position:0% can be reached from the origin but crossing exactly n minus one Bragg align:start position:0% crossing exactly n minus one Bragg align:start position:0% crossing exactly n minus one Bragg planes align:start position:0% planes align:start position:0% planes so we can look also add a brilliant zone align:start position:0% so we can look also add a brilliant zone align:start position:0% so we can look also add a brilliant zone for a system where the atoms are not align:start position:0% for a system where the atoms are not align:start position:0% for a system where the atoms are not perfectly in the perfect square lattice align:start position:0% perfectly in the perfect square lattice align:start position:0% perfectly in the perfect square lattice but are offset a bit making sort of say align:start position:0% but are offset a bit making sort of say align:start position:0% but are offset a bit making sort of say a triangular lattice and as we can see align:start position:0% a triangular lattice and as we can see align:start position:0% a triangular lattice and as we can see here the first billion zone is it such align:start position:0% here the first billion zone is it such align:start position:0% here the first billion zone is it such such a hexagon and the second one align:start position:0% such a hexagon and the second one align:start position:0% such a hexagon and the second one already gets a bit more difficult by align:start position:0% already gets a bit more difficult by align:start position:0% already gets a bit more difficult by forming a star shape and the third one align:start position:0% forming a star shape and the third one align:start position:0% forming a star shape and the third one is again so to say FX agon and it goes align:start position:0% is again so to say FX agon and it goes align:start position:0% is again so to say FX agon and it goes on like that align:start position:0% on like that align:start position:0% on like that okay so and then so what information is align:start position:0% okay so and then so what information is align:start position:0% okay so and then so what information is the brilliance don't hold on what does align:start position:0% the brilliance don't hold on what does align:start position:0% the brilliance don't hold on what does it give us the short vectors in the align:start position:0% it give us the short vectors in the align:start position:0% it give us the short vectors in the Brillion zone or on its boundary align:start position:0% Brillion zone or on its boundary align:start position:0% Brillion zone or on its boundary characterized States in a system with align:start position:0% characterized States in a system with align:start position:0% characterized States in a system with lattice period periodicity for example align:start position:0% lattice period periodicity for example align:start position:0% lattice period periodicity for example phone out or or electron state but for align:start position:0% phone out or or electron state but for align:start position:0% phone out or or electron state but for that the whole of the video thanks and align:start position:0% that the whole of the video thanks and align:start position:0% that the whole of the video thanks and this code for this demonstration was align:start position:0% this code for this demonstration was align:start position:0% this code for this demonstration was taken and editors from Mathematica align:start position:0% taken and editors from Mathematica align:start position:0% taken and editors from Mathematica demonstration since made by their slope align:start position:0% demonstration since made by their slope align:start position:0% demonstration since made by their slope cloth |