Recent content by ck00

What is the meaning of change of Hilbert space?

Thank you for your answering. I have a follow-up question. Consider 2x2 Hamiltonian H=H0+H'. Let Φ_a and Φ_b be two eigenstates of H0 and ψ_a and ψ_b be two eigenstates of H. What is the relation between {Φ_a, Φ_b} and {ψ_a, ψ_b}? Are they just linear combination of each other?

Maybe the form of wavefunctions will depend on the gauge, probably just an addition of phase factor in wavefunction. But all the physical measurements should be independent of gauge.

Hi all, I have a question about the concept of complete set when I apply the perturbation theory in two situations -Finite Hilbert Space and Infinite Hilbert Space. Consider a Hamiltonian H=H0+H', where H0 is the unperturbed Hamiltonian and H' is the perturbed Hamiltonian. Let ψ_n be the...

Incoming electron is only required to carry a K.E. which is larger than the difference in energy levels but not required to be a specific amount. As it can give out part of its energy to the atom, unlike photon which can give either all its energy or nothing.

For example, how to obtain E_(yz,xz)(l,m,n) from E_(xy,xz)(l,m,n)?

The classical textbook, Introduction to solid state physics by Charles Kittle said: "If we encounter a Bloch function written as ψ_{k’}(r)=exp(i{k’}r) u_{k’}(r), with k’ outside the first zone, we may find a suitable reciprocal lattice vector G such that k=k’+G lies within the first Brillouin...

Help please! Where can I start if I want to learn Quantum Spin Hall Effect? I have learned the some fundamental ideas of integer quantum hall effect by myself. Under this background, what more should I read? cause I really can't find any notes or videos that are teaching about QSHE. I am now in...

um...then what is y?

I got trouble in dealing with this kind of system. For example, Ay``+By`+Cy=0 where y=transpose(y1 y2) A=(1 0 0 1) B=(0 1 1 0) C=(1 1 1 1) May someone give me a book name?:smile:

oh,ya, you are right, it's just a typo. Thanks for teaching:smile:

can anyone help?

If I want to derive the matrix representation for operator Q in the |S1=1/2 ,m1> |S2=1/2 ,m2 > basis, where |Si,mi> are common eigenstates of S2 , Si,z for the ith particle. And I do it in this way: <↑↑|Q|↑↑> <↑↑|Q|↑↓> <↑↓|Q|↓↑> <↑↑|Q|↓↓> <↑↓|Q|↑↑> <↑↓|Q|↑↓> <↑↓|Q|↓↑> <↑↓|Q|↓↓> ...

does anyone know it?

why do we say that a classically behaved gas is non-degenerate and a quantum behaved gas is degenerate? I can't get why the word of "degeneracy" here can distinguish two kinds of behavior of gas.