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2 votes

What is the state of the light emitted by an esemble of independent single photon emitters?

Upon proper excitation, single molecules (e.g. fluorescent dyes, quantum dots, etc.) spontaneously emit single photons, namely Fock states |1⟩. Most substances have a quantum yield that is much ...
1 vote

Photon though a single-slit and uncertainty in the $z$- (longitudinal) direction

In quantum mechanics, The expectation value of the energy is preserved whenever the system is freely evolving, but energy itself is not necessarily conserved. The electron going through the slit does ...
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0 votes

Squeezed vacuum state

The ellipse he draws is a cartoon of the Wigner function of the state, which is not discussed in the book. The Wigner function of a squeezed vacuum state is: $$ W(x,y) \propto \mathrm{exp}\big[-e^{2\...
  • 114
1 vote

Where can one find the expression for the origin of the Hamiltonian of the Kerr nonlinear interaction in an optical cavity?

As with all quantum theories, the quantum theory of a Kerr medium comes from a quantization of the classical theory. In a nonlinear medium, the electric flux density $\mathbf{D}$ can be expanded in ...
  • 12.7k
0 votes
Accepted

CNOT gate path interference

Your problem is that you are assuming the two photons arrive at the first beam-displacer with zero relative delay, but their relative delay at the input is in fact a free parameter in the experiment. ...
  • 114
1 vote

SPDC One Arm vs Very Weak Coherent state

The state generated by SPDC is a two-mode squeezed vacuum state, which can be written in the Fock basis as: $$ |\Psi\rangle_{s,i} = \sum_{n=0}^{\infty} \frac{\mathrm{tanh}^n r}{\mathrm{cosh}\;r} |n,...
  • 114
2 votes

Projection Postulate of Quantum Mechanics. Where does the Projection occur in the detection process?

This question is asking about the location of theHeisenberg cut in an experiment. Different theories* of quantum mechanics have different answer to this question. The Copenhagen theories (or textbook ...
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