Quantum Communication Using Semiconductor Quantum Dots

Abstract

Worldwide enormous efforts are directed towards the development of the so-called quantum internet. Turning this long sought-after dream into reality is a great challenge that will require breakthroughs in quantum communication and computing. To establish a global, quantum-secured communication infrastructure, photonic quantum technologies will doubtlessly play a major role, by providing and interfacing essential quantum resources, e.g., flying-and stationary qubits or quantum memories. Over the last decade, significant progress has been made in the engineering of on-demand quantum light sources based on semiconductor Quantum Dots, which enable the generation of close-to-ideal singleand entangled-photon states, useful for quantum cryptography tasks. This review focuses on implementations of, and building blocks for, quantum communication using quantum-light sources based on epitaxial semiconductor quantum dots. After reviewing the main notions of quantum cryptography (section 1) and introducing the devices used for single-photon and entangled-photon generation (section 2), it provides an overview of experimental implementations of cryptographic protocols using quantum dot based quantum light sources (section 3). Furthermore, recent progress towards quantum-secured communication networks as well as building blocks thereof is summarized (section 4). The article closes with an outlook, discussing future perspectives in the field and identifying the main challenges to be solved.

Efficient room-temperature molecular single-photon sources for quantum key distribution

“…Few experiments have shown the ability to generate quantum keys by exploiting deterministic single-photon source. Examples include quantum dots [12,13,14,15,16] and color centers in diamond [17], where promising results were obtained in terms of key generation rates as compared to standard QKD systems. However, most of these systems need cryogenic temperatures, which involve higher costs and limited portability.…”

High extraction efficiency source of photon pairs based on a quantum dot embedded in a broadband micropillar cavity

“…Low multiphoton contribution (Fig. 3d) was observed at zero delay, with g (2) (0) x =0.016(3) and g (2) (0) xx =0.009(2) for exciton and biexciton, respectively. To test the indistinguishibility of the consecutively emitted photons, Hong-Ou-Mandel (HOM) interference experiments were performed.…”

“…Quantum dots have shown outstanding potential as emitters of quantum light with promising applications in quantum communication [1][2][3][4][5] and quantum computation [6], the latter being a possible path to demonstrate quantum advantage. They can be excited resonantly and coherently to generate on-demand single photons [7][8][9] and photon pairs [10][11][12][13].…”

“…FIG.3:(a) Summary of lifetime values obtained for all the measured devices (b) Lifetime of biexciton photon for an oncavity and an off-cavity emitter (c) Rabi oscillations of the biexciton. (d) The autocorrelation measurements of the exciton and biexciton photons yielding g(2) (0)x=0.016(3) and g(2) (0)xx=0.009(2).…”