Consider N non-interacting electrons confined to a two-dimensional square well of dimensions a × a. Derive an expression for the Fermi energy of this system in terms of the areal density σ = N/a2 and calculate the corresponding density of states. Show all steps.
Consider N non-interacting electrons confined to a two-dimensional square well of dimensions a × a. Derive...
Consider a two-dimensional non-interacting and non-relativistic gas of N spin-1/2 fermions at T 0 in a box of area A. (a) Find the Fermi energy εF. (b) Show that the total energy is given by E- NE. 2
Problem 4. Low-dimensional materials play an important role in nanotechnology. Consider a two-dimensional Fermi gas of N non-interacting electrons confined to a plane of area A. Find the Fermi energy &r (in terms of A and N) and the average electron energy. Find (analytically) the chemical potential p as a function of er and T.
Calculate the Fermi energy for electrons in a 4-dimensional infinite square well. (See Griffiths Quantum Mechanics 2nd edition, problem 5.34 for reference. NOTE: The problem in Griffiths is for a 2-dimensional infinite square-well, NOT a 4-dimensional infinite square well.)
Graphene is a single graphitic layer of carbon atoms, which has the remarkable feature that electrons in graphene behave as two dimensional massless relativistic fermions with a "speed of light, graphene 《 c. Andre Geim and Konstantin Novoselov were awarded the 2010 Nobel Prize in Physics "for groundbreaking experiments regarding the two-dimensional material graphene". a) ) Calculate the density of states as a function of energy for massless relativistic electrons in graphene with for a system of size L (note...
Density of states in 2 dimensions. Consider graphene, a 2 dimensional material which has a very unusual energy dispersion: E(k) -hkvF where VFis called the Fermi velocity and vF 10 m/s for all values of k. In k-space the dispersion looks like cone, called the Dirac cone, because the electrons behaves as relativist particles. The Fermi energy for intrinsic graphene is Ef-0, but can be electrostatically doped to Ef O - hkv; where Vris called the Fermi velocity and V...
a) Consider the above equation, 2T obtained for three dimensions. Following the same lines of reasoning above, show that in two dimensions, this equation becomes: g,A where A is the two-dimensional area of the two-dimensional sample b) Find kF as a function of N and A for such a two-dimensional system e) Find the Fermi energy for such a two-dimensional system d) At nonzero temperature, we want to compute the chemical potential (T). By imposing that the average number of...
4. 3D Infinite Square Well Perturbation (20 pts) Consider the three-dimensional infinite cubic well: otherwise The stationary states are where n, ny, and n, are integers. The corresponding allowed energies are Now let us introduce the perturbation otherwise a) Find the first-order correction to the ground state energy b) Find the first-order correction to the first excited state 4. 3D Infinite Square Well Perturbation (20 pts) Consider the three-dimensional infinite cubic well: otherwise The stationary states are where n, ny,...
a) Consider the above equation, 2T obtained for three dimensions. Following the same lines of reasoning above, show that in two dimensions, this equation becomes: g,A where A is the two-dimensional area of the two-dimensional sample b) Find kF as a function of N and A for such a two-dimensional system e) Find the Fermi energy for such a two-dimensional system d) At nonzero temperature, we want to compute the chemical potential (T). By imposing that the average number of...
4. (20 points) Infinite Wells in Three Dimensions a) Consider a three dimensional in- finite rectangular well for which L -L, Ly-2L, ald L2-3L. In terms of quantum numbers (e.g. nz, ny, and n.), M. L, and ћ. write down an expression for the energies of all quantum states. (b) Find the energies of the ground state and the first three lowest lying energies. As in part (b), for each energy level, give the quantum numbers n, ny, n and...
4. A particle moves in a periodic one-dimensional potential, V(x a)-V(x); physically, this may represent the motion of non-interacting electrons in a crys- tal lattice. Let us call n), n - 0, +1, t2, particle located at site n, with (n'In) -Sn,Let H be the system Hamiltonian and U(a) the discrete translation operator: U(a)|n) - [n +1). In the tight- binding approximation, one neglects the overlap of electron states separated by a distance larger than a, so that where is...