Control engineering of continuous-mode single-photon states: a review

Abstract

In this survey, we present single-photon states of electromagnetic fields, discuss discrete measurements of a single-photon field, show how a linear quantum system responds to a single-photon input, investigate how a coherent feedback network can be used to manipulate the temporal pulse shape of a single-photon state, present single-photon filter and master equations, and finally discuss the generation of Schrödinger cat states by means of photon addition and subtraction.

Flying-qubit control via a three-level atom with tunable waveguide couplings

“…The obtained solution (17) is closely related to the singlephoton generation condition (12) with a two-level atom. They are similar in that both denominators represent the total number of photons to be released in the future.…”

“…The control of flying qubits must be actuated by some manipulatable standing quantum system (i.e., an atom). In the view of quantum input-output theory [10][11][12], the incoming and outgoing flying qubits form the quantum input and output of the standing quantum system. Roughly speaking, we may encounter the following three classes of control tasks: (1) the generation of flying qubits with vacuum quantum inputs [13][14][15][16][17][18][19], (2) the catching of flying qubits that yields vacuum quantum outputs [7][8][9]15,[20][21][22], and (3) the transformation of flying qubits with both nonvacuum quantum inputs and outputs [18,[23][24][25][26][27].…”

Flying-Qubit Control via a Three-level Atom with Tunable Waveguide Couplings

“…To define the single-photon state |1 ξ with shape function ξ(t), let us start with the temporal annihilation operator b(t) = +∞ −∞ e −iωt b(ω)dω of the traveling field in a waveguide, where b(ω) is the annihilation operator associated with mode ω. The state of a flying qubit that contains exactly one photon in a single channel can be described as [22,50]…”