Questions tagged [photonics]
It is the branch of physics and engineering concerned with the properties and transmission of photons. Use this tag for those questions about photonics which are relevant to quantum computing.
2
votes
1answer
39 views
What are the ranges of the four $q$ parameters in the magic simplex of Bell states formula?
Equation (7) in the 2012 paper, "Complementarity Reveals Bound Entanglement of Two Twisted Photons" of B. C. Hiesmayr and W. Löffler for a state $\rho_d$ in the "magic simplex" of Bell states
\begin{...
3
votes
1answer
76 views
How does quantum memory work using atoms?
I was trying to learn quantum memory and went through some papers, websites, etc.
The current understanding I have (which I'm not sure is right) is this: Two photons are prepared together which are ...
1
vote
1answer
115 views
How to explain polarization using photon spin?
I know how polarization filters work using EM waves. Can somebody help me in understanding how they work using photons?
1
vote
1answer
42 views
Implementing BB84 protocol with easily-obtained consumer hardware
Following on from my question on educational quantum computing toys, I was wondering whether it is possible to implement the BB84 key distribution protocol with easily-obtained consumer hardware - ...
2
votes
2answers
59 views
Phase shifter acting on double rail states
In Nielsen and Chuang, it is stated that the photonic phase shift gate acts on the single photon states as $P|0\rangle \ = \ |0\rangle$ and $P|1\rangle \ = \ e^{i\Delta}|1\rangle$, where $\Delta \ = \ ...
5
votes
2answers
79 views
Multi-photon states in photonic quantum computing?
Within photonic quantum computing, one of the ways to represent information is the dual-rail representation of single-photon states ($c_0|01\rangle \ + \ c_1|10\rangle$). Is it possible to utilize ...
3
votes
2answers
92 views
Time-bin encoding qudits
Time-bin encoding is a technique used in Quantum information science to encode a qubit of information on a photon. Wikipedia
Is there a generalization for $n$-th level qudits?
2
votes
0answers
52 views
3
votes
2answers
111 views
Polarization and qubit information
It is my understanding that light, and its polarization, is used to transfer information in quantum computers, but how can the information encoded in say, an electron also be stored in light? I ...
9
votes
3answers
198 views
Do any educational quantum computing toys or devices exist?
Question inspired by this article from IEEE Spectrum on blocks containing different polarization filters for use in classrooms, and my previous question on representing the three-polarizing-filter ...
6
votes
2answers
163 views
Analyzing the three-polarizing-filter experiment as a quantum circuit
In the three-polarizing-filter experiment, two orthogonal polarizing filters block all light but then allow some amount when a third polarizing filter is placed oriented at a 45 degree angle between ...
7
votes
2answers
119 views
What about BosonSampling can be publicly verified?
Boson Sampling, sometimes stylized as BosonSampling, is an attractive candidate problem to establish quantum supremacy; the engineering problems appear more surmountable than those associated with a ...
3
votes
1answer
265 views
What does negative probability represent?
"Negative energies and probabilities should not be considered as nonsense. They are well-defined concepts mathematically, like a negative of money." -Paul Dirac
The abstract from Photon-phonon-photon ...
2
votes
1answer
77 views
Photonic Circuit Idea (Does this already exist?)
I have had a few ideas for circuits that I would like to get feedback on (do such things already exist, what utility they serve, etc).
Any suggestions on how I might graphically render these?
...
15
votes
2answers
252 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 ...
