Photonic transistor and router using a single quantum-dot-confined spin in a single-sided optical microcavity

Abstract

The future Internet is very likely the mixture of all-optical Internet with low power consumption and quantum Internet with absolute security guaranteed by the laws of quantum mechanics. Photons would be used for processing, routing and com-munication of data, and photonic transistor using a weak light to control a strong light is the core component as an optical analogue to the electronic transistor that forms the basis of modern electronics. In sharp contrast to previous all-optical tran-sistors which are all based on optical nonlinearities, here I introduce a novel design for a high-gain and high-speed (up to terahertz) photonic transistor and its counterpart in the quantum limit, i.e., single-photon transistor based on a linear optical effect: giant Faraday rotation induced by a single electronic spin in a single-sided optical microcavity. A single-photon or classical optical pulse as the gate sets the spin state via projective measurement and controls the polarization of a strong light to open/block the photonic channel. Due to the duality as quantum gate for quantum information processing and transistor for optical information processing, this versatile spin-cavity quantum transistor provides a solid-state platform ideal for all-optical networks and quantum networks.

Tunable single-photon quantum router

“…One of the most relevant devices for the operation of a quantum network is a quantum router, whose primary function in the simplest configuration is to send or route an incident photon into one of the two output channels [10]. Recently, there have been several theoretical and experimental proposals for quantum routers based on several different structures, such as CRWs [11][12][13][14][15][16], whispering gallery resonators [17][18][19][20][21], waveguide-emitter systems [22,23], superconducting qubits [24], and quantum electrodynamics systems [25,26]. In the latter context, Zhou and co-workers [11,12] proposed an experimentally accessible single-photon routing scheme comprising two quantum channels connected by a resonant cavity with a single-type three-level atom embedded in it.…”

Optical Fredkin gate assisted by quantum dot within optical cavity under vacuum noise and sideband leakage

“…c where the reflectances and phase shifts are |r h (ω)| = |r 0 (ω)|≈1 and ϕ rh (ω)≈0, ϕ r0 (ω)≈π for g/κ = 2.4, and γ/κ = 0.1 with κ s → 0 and ω = ω c (frequencies: external field = cavity mode) 2,4,[11][12][13]15,[41][42][43][44][45][46][47][48][49][50][51][52][53][54] . According to the reflection operator, Eq.…”

“…To obtain scheme for quantum information processing with the reliable performance, the most important task is to maintain the coherence of quantum state when to operate the procedure of multi-qubit controlled operations. In quantum dot (QD)-cavity system, which consists of an injected excess electron and a confined negatively charged exciton (X − ) in optical cavity 2,4,[11][12][13]15,[41][42][43][44][45][46][47][48][49][50][51][52][53][54] , quantum information can be well stored for a long electron-spin coherence time (T 2 e~μ s) 43,45,46,[55][56][57] and a limited spin relaxation period (T 1 e~m s) 42,50,58,59 against the influence (decoherence effect) of environment. Therefore, several diverse quantum information processing schemes have been designed between photons and electrons in the QD-cavity system, as quantum controlled gates 21,[24][25][26]30,31,[47][48][49]52,60 , quantum communications [10][11][12]…”

Dynamical control of the emission of a square microlaser via symmetry classes

“…Accordingly, the dynamical control of resonator properties has become an intense field of research. Some proposals are still theoretical [7][8][9], whereas others have been applied successfully in experiments [10][11][12][13][14][15][16].…”