Recent content by lfqm

1.- The hilbert space approach does not include distributions (free particle, for example) nor mixed states. 2.- The C* algebra approach does not account for unbounded operators. 3.- Rigged Hilbert space approach does not include mixed states. I'm not sure about path integral formulation... so...

Ok, at 0 tenperature the ground state is a coherent state with Alfa=0... But, the first excited state at 0 temperature is the fock state |1>? i.e. the usual spectrum.

So, the hamiltonian isn't modified? At 0 temperature I study the usual spectrum of the hamiltonian and at finite temperature I use the density operador given in statistical mechanics?

Hi! These days I've been studying thermodynamics of quantum systems, and in so a very basic doubt come to me... I hope you guys can help me: When we study the usual hamiltonians of quantum mechanics (H-atom, harmonic oscillator, etc.)... Are these hamiltonians modeling the system at...

Thanks Avodyne! That's the reason! :biggrin:

First of all, thanks for the answer f95toli. That's exactly my point, every quantum optics book starts assuming that form (with a fixed amplitude) for a classical single mode field, even though you can multiply that same solution by an arbitrary constant and still satisfy maxwell equations.

Thanks for your answer, but I think your advice does not apply in this case, as the electric field operator is not a projection (its trace is zero).

Hi guys, I'm trying to understand why does the amplitude of the electric field operator in a cavity is fixed at \left ( \displaystyle\frac{\hbar\omega}{\epsilon_{0}V} \right )^\frac{1}{2} Every book I read says it is a normalization factor... but, normalizing an operator?, what is the meaning...

Hi guys! I'm making my Phd on cavity QED but wish to move towards superconducting quantum circuits, could you give me some good references (articles or books) at an introductory level (for self-study)? Thanks in advance

Hi guys! I've got this system in which Eherenfest classification of "order" is assumed to be ok. So I took my free energy function G(T,P) and start differentiating. I found just one phase transition between two phases, the problem is the phase transition is of different order depending on the...

Are there any known (collective spin) operators to raise or lower the quantum number s in \left|{s,m}\right> spin states? I'm trying to construct coherent states varying the quantum number s instead of the well known spin coherent states varying m. I found a coherent-like state similar to the...

Hello colleagues, hope you can help me. The Dicke model describes a system of N two-level atoms cooperatively interacting with a single mode of an electromagnetic field as follows...

I'm not really into representation theory, but as far as I understand, the only thing that I get from there is the multiplicity of the eigenvalues... Could you explain your answer using linear algebra? I'm looking for the other two common eigenvectors. Thank you

Hi guys, my quesion is quite simple but I think I need to give some background... Let's suppose I have 3 qubits, so the basis of the space is: \left\{{\left |{000}\right>,\left |{001}\right>,\left |{010}\right>,\left |{100}\right>,\left |{011}\right>,\left |{101}\right>,\left...

The first postulate of quantum mechanics says that every physical system is associated with a separable complex Hilbert space, however this does not hold for a free particle, where the basis is uncountable (all the momentum kets). I think it also does not hold for a free falling particle...