Recent content by ck00
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Graduate Finite Hilbert Space v.s Infinite Hilbert Space in Perturbation Theory
What is the meaning of change of Hilbert space?- ck00
- Post #6
- Forum: Quantum Physics
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Graduate Finite Hilbert Space v.s Infinite Hilbert Space in Perturbation Theory
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?- ck00
- Post #5
- Forum: Quantum Physics
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Graduate Initial wave function for an electron in a magnetic field
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.- ck00
- Post #2
- Forum: Quantum Physics
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Graduate Finite Hilbert Space v.s Infinite Hilbert Space in Perturbation Theory
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...- ck00
- Thread
- Finite Hilbert Hilbert space Infinite Perturbation Perturbation theory Space Theory
- Replies: 7
- Forum: Quantum Physics
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Undergrad Do electrons need specific energies to excite electrons
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.- ck00
- Post #5
- Forum: Quantum Physics
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Graduate How to do cyclic permutation on interatomic matrix elements?
For example, how to obtain E_(yz,xz)(l,m,n) from E_(xy,xz)(l,m,n)?- ck00
- Thread
- Cyclic Elements Matrix Permutation
- Replies: 1
- Forum: Atomic and Condensed Matter
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Graduate Question about Bloch function in Reduced Zone Scheme
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...- ck00
- Thread
- Function
- Replies: 1
- Forum: Atomic and Condensed Matter
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Graduate Help Where can I start if I want to learn Quantum Spin Hall Effect?
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...- ck00
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- Hall effect Quantum Quantum spin Spin
- Replies: 1
- Forum: Quantum Physics
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Undergrad Is there any book talking about system of 2nd order ODE?
um...then what is y?- ck00
- Post #3
- Forum: Differential Equations
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Undergrad Is there any book talking about system of 2nd order ODE?
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:- ck00
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- 2nd order Book Ode System
- Replies: 4
- Forum: Differential Equations
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Graduate Problem in constructing Matrix representation in |↑↓> basis
oh,ya, you are right, it's just a typo. Thanks for teaching:smile:- ck00
- Post #4
- Forum: Quantum Physics
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Graduate Problem in constructing Matrix representation in |↑↓> basis
can anyone help?- ck00
- Post #2
- Forum: Quantum Physics
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Graduate Problem in constructing Matrix representation in |↑↓> basis
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|↓↓> ...- ck00
- Thread
- Basis Matrix Representation
- Replies: 3
- Forum: Quantum Physics
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Graduate What is the meaning of non-degenerate in statistical mechanics?
does anyone know it? -
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Graduate What is the meaning of non-degenerate in statistical mechanics?
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.