Thank you, Cthugha! Yes, I want it for a detector. I can cool it down to 4.2K too. Single photon sensitivity is also required. I need the maximum absorption for the thinnest possible film, say a few nano meter. Spectral resolution is not an issue as long as either telecom freqs i.e. 1310 or 1550...
Thank you, f95toli! In fact, I am interested in telecom wavelengths: 1550 nm or 1310 nm. Since the number of photons are very limited we need to absorb as much as we can.
Hi all,
I am looking for the best material for IR (infra red) absorption, preferably something that I can make it into a thin film; any material that would work from semiconductors, metals to more exotic materials like graphene or...
I appreciate your help.
Thank you
Thanks, Sambristol! In fact my question on "kinetic capacitance" comes from studying "quantum phase slip". I understand it as a combination of coefficients with the dimension of capacitance in the "effective action" introduced by Golubev and Zaikin; however, I was hoping to get some physical...
What is "kinetic capacitance" in superconductors or in solid state in general?
Hi,
I would appreciate it if anyone could explain to me what "kinetic capacitance" is, particularly in the context of superconductors or solids.
I understand "kinetic inductance" which comes from the kinetic...
Hello,
I would appreciate it if anyone could help me with this problem: can there be any instantonic contribution to the following generic two-points function?
\left \langle \varphi(x) \varphi(y) \right\rangle= \int D\varphi D A \varphi(x) \varphi(y) \exp \left( -S_E...
Hello,
I need to measure the complex-optical conductivity of some materials. The problem is that I can only measure the imaginary part of the complex conductivity only for limited wavelengths between 1030 nm and 2300 nm.
From Kramers-Kronig relations, we know that the real and imaginary...
Hi,
I appreciate any help in this regard:
People have used cathodoluminescence to study defects in insulators by having energetic electron beam on the defect and observing the luminescence.
I want to see if I can do the same thing instead by putting gates around that defect. I can also...
Hello,
Conductivity \sigma (\omega, k) in Fourier space is defined by
J(\omega, k)= \sigma (\omega, k) A(\omega, k)
In most cases the local limit of k\rightarrow 0 is a good approximation particulalry in type I superconductors and HTC superconductors.
I am interested in cases...
I am not sure if I understood your question exactly and my reply may sound trivial. Anyway,
when you have a symmetry there are invariants associated with each of those symmetries (Noether's Theorem). In other words some quantities will be conserved during, let's say, a collision experiment like...
Hello,
Assuming that I have a pure U(1) gauge theory. The partition function can be written as
Z=\int D(A) \exp (-F_{\mu\nu} F^{\mu\nu})
If I want to find the effective action in terms of an external classical field I can write it in terms of
A\rightarrow A+B where B is background and then...
Could anyone please, explain the connection between the Free Energy and the Action?
I know the definitions of each but not sure about the connection.
I read somewhere that the free energy is the same as the action when calculated "on-shell". What does this "on-shell" thing mean in this...
Thanks a lot, DrDU! I am just not sure if I understood exactly what you meant for (2)
My effective action is complex and non local but fortunately remains quadratic in terms of A and \psi or combination of these two. Therefore I can technically integrate over both A and \psi in the path...
Hi,
In calculating the conductivity from the Kubo method
j_{\mu}=\int dx' K_{\mu \nu} (x,x') A^{\nu}(x')
in literature ( e.g. in Condensed Matter Field Theory by Altland and Simons) you find that
K_{\mu \nu}(x,x')= Z^{-1} \frac{\delta^2}{\delta A_{\mu}(x) \delta A_{nu}(x')}...
EM response function of the "Phase Action" of a BCS superconductor
Hello,
I am looking for a paper in which people calculated the EM response of phase action of A BCS SC. In the book "Condensed Matter Field Theory" by Altland and Simons, on page 393 they mention such a thing in the discussion...