Questions tagged [optical-quantum-computing]
For questions about the specific realization of quantum computing that uses photons as qubits. Examples of gates include the Fabry-Perot cavity or linear optical components like beamsplitters. Questions with this tag can ask about both theory and practice, as long as it relates to this specific realization.
6
questions
25
votes
3
answers
3k
views
Why do optical quantum computers not have to be kept near absolute zero while superconducting quantum computers do?
This is a follow-up question to @heather's answer to the question : Why must quantum computers be kept near absolute zero?
What I know:
Superconducting quantum computing: It is an implementation of ...
- 17.5k
20
votes
3
answers
1k
views
Is it possible to "calculate" the absolute value of a permanent using Boson Sampling?
In boson sampling, if we start with 1 photon in each of the first $M$ modes of an interferometer, the probability of detecting 1 photon in each output mode is: $|\textrm{Perm}(A)|^2$, where the ...
10
votes
1
answer
719
views
How do you apply a CNOT on polarization qubits?
I read that a qubit can be encoded in a polarization state (horizontal or vertical polarization of a photon). How do you perform two-qubit operations on a polarization qubit?
- 885
5
votes
2
answers
341
views
What is the correct sign in the unitary evolution operator of a beam splitter?
I'm a bit confused about which is the correct sign in the unitary evolution operator of a beam splitter.
In paper Digital quantum simulation of linear and nonlinear optical elements author uses the ...
- 267
2
votes
1
answer
214
views
Comparing technical limitations of major quantum computing approaches
As far as I know, major quantum computing approaches include superconducting qubits, trapped ions, nuclear magnetic resonance qubits, and free space quantum optics. I guess two main technical ...
- 81
2
votes
1
answer
515
views
Hamiltonian for Single-photon, Single-atom QED Cavity
Equation 7.71 of Nielsen and Chuang's Quantum Computation and Quantum Information gives the Hamiltonian for a two level atom and single mode photons in a cavity as:
$H = \hbarωN + δZ + g(a^†σ_− + aσ_+...
- 159