Recent content by shawl

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    Metable states in a Laser

    A1 to B1 belongs to quantum dynamics, and A1 to A2 is due to thermal diffusion. Eletron itself doesn't know which state it should go, but the detail physical process will decide where the electron is going
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    Metable states in a Laser

    I do not get your point, either. Here's my suggestion. Metastable state is in company with a certain state. In general, there is a small gap between their energy levels (Metastable level belows certain one). Given 2 certain states, A and B, and suppose their have some metastable states...
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    Spin direction through ferromagnetic material

    You have to clarify what kind of ferromagnetic material is. there is no common answer for such a question. Give you a suggestion, please refer to the concept of spin valve.
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    Weak Anti Localisation concept

    Abstracted from Wikipedia, "In a system with spin-orbit coupling the spin of a carrier is coupled to its momentum. The spin of the carrier rotates as it goes around a self-intersecting path, and the direction of this rotation is opposite for the two directions about the loop. Because of this...
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    How does or does not BCS theory explain Meissner's Effect?

    In my knowledge, BCS did make a deep prediction in the situation of the weak electromagnetic field of type-I superconductor. Please refer to the book <theory of superconductivity> written by J. R. Schrieffer, who is the third person in BCS theory. Surely spontaneous symmetry breaking and...
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    Density-density interaction in Luttinger liquids

    Agree with OhYoungLions. Fourier transformation. The variable x in Eq. (6) strictly accords with momentum space。
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    How does or does not BCS theory explain Meissner's Effect?

    That was one of significant paper exciting everyone in the field of superconductor. In history of superconductor,"two current" model (Normal current and superconducting one) was first proposed by London brothers, explaining such zero-resistance conducting phenomenon. Company with...
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    What happens when you connect a ptype semiconductor to a metal conductor?

    The electric properties of a metal can be viewed as a highly degenerated N-type semiconductor. Therefore, P-metal can be treated as a pn diode. And it properties depends, as what yasir.ustb stated, on the work function of each materials.
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    Negative absorption peak in FTIR

    Something are exciting over the UV illumination processes.
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    What's the relationship between phonon spectrum and thermal conductivity

    Thank you! You really give me a lesson. Noted the eq. 6 in the paper you given. The thermal conductivity to be calculated requires not only the group volecity v but also the relaxation time torr. Please refer to "proposal for a single molecule field effect transistor for phonons" (Phys...
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    Impurity State Green's functions

    The intermediate term is the Self-energy term. It is calculated by infinite iteration. It also can be solved in the limit of Born approximation The detail solution you may find please refer to the "Many particle physics" authored by G. Mahan. Please take a good book to learn Green's function...
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    Cold temperature measurement

    It requires ultra high vaccum. And the cooling technology can be utilized is "Laser cooling" and "Magnetic refrigeration".
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    What's the relationship between phonon spectrum and thermal conductivity

    To comparison for the thermal conductivity of two different materials, you need to know the respective velocity of phonon. Without the velocity, it is hard to do anything. I dont know what phonon spectrum you have. Generally, the spectrum respresents the number of phonon (axis Y) at each...
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    Impedance in a superconductor

    There are one thing we need to clarify. For the second kind superconductor, as called high temperature superconductor, the magnetic flux can be enter into the superconducting bulk, and it will be pined at the center of defect. Around the flux, one can image a superconducting circuit current is...
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    Band bending

    Yes, the amount of potential change depends on the donor concentration. Or we can say, the degree of the conduction (valence) band bending will be affected due to the dopant.