A research field within general optical physics concerned with light and its material interaction: where light is modelled by full quantum mechanical description.

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Scalar product of coherent states

We suppose for semplicity to have a 1D oscillator, but this is a question abaout the general CCR algebra in oscillators, second quantization, quantum field theory etc. We know coherent states are a ...
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How many stabilised qubits have been achieved in Quantum Computing?

The latest I read is 3 but that was in Oct. With Lene Hau of Harvard's "frozen light" and with quantum donuts, newer strategies for stabilization are appearing, but the problem of keeping the qubit in ...
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How to count photons

How are photons counted? What is the experimental setup used to count photons from a laser or even a lamp? Of course, in the case of the lamp, I would be able to count only the photons that pass ...
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670 views

Informational capacity of qubits and photons

How much information is contained in one qubit? A qubit is defined in Wikipedia as $a\left|0\right> +b\left|1\right>$, where a and b are complex numbers subject to $a^2 + b^2 = 1$. One complex ...
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Nonlinear optics as gauge theory

the widely used approach to nonlinear optics is a Taylor expansion of the dielectric displacement field $\mathbf{D} = \epsilon_0\cdot\mathbf{E} + \mathbf{P}$ in a Fourier representation of the ...
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597 views

Unambiguous distinguishing of quantum states by local measurement

Let's have two orthogonal n-particle quantum states: $|\psi \rangle$ and $|\phi \rangle$. In theory it is always possible to make an unambiguous measurement. However, things get complicated when one ...
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1answer
284 views

Which qubit states are accessible with linear optics operations?

Given a quantum state of $n$ qubits, and being restricted to linear optics (that is, the output annihilation operators are linear combinations of the input annihilation operators): Which states are ...
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534 views

Alkali atom - photon interaction in zero magnetic field

An alkali atom has a single outer electron that interacts with incoming photons of the right wavelength (for alkalies it's in the visible & IR range). If there is an external magnetic field, the ...
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Explanation of the experiment with Mach–Zehnder interferometer (self-interference of a single photon)

Here is the description of experiment which uses Mach–Zehnder interferometer http://en.wikipedia.org/wiki/Mach-Zehnder or http://departments.colgate.edu/physics/research/Photon/root/ajpbs02.pdf ...
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In optics, how does the vacuum state compare to thermal radiation?

In quantum optics, a perfect absorber of light is said to emit the "vacuum field". In practice, any beam dump will be at finite temperature, so it will emit blackbody radiation. How do these fields ...