2010/11/23 by J. M. Elzerman, K. M. Weiss, Elzerman, J. M. +5
Computer Science · Physics and Astronomy · #FOS: Physical sciences #Mesoscale and Nanoscale Physics (cond-mat.mes-hall) #Quantum Information and Cryptography #Quantum and electron transport phenomena #Semiconductor Quantum Structures and Devices
paper · pdf · doi:10.48550/arxiv.1011.5203
openalex publication_date 2010/11/23 · openalex created_date 2025/10/10 · openalex updated_date 2026/07/28
A holy grail of photonics research is the realization of a laser that uses a single quantum emitter as the gain medium. Such a device would exhibit a plethora of new features, including lasing without a well-defined threshold and output intensity fluctuations that remain below the shot-noise limit. While single-atom lasers have been demonstrated, compact devices capable of continuous-wave operation require monolithic structures involving a solid-state quantum emitter. Here, we report the observation of steady-state laser amplification in Raman transitions between the lowest-energy entangled spin states of a quantum-dot molecule. Absorption and resonance fluorescence experiments demonstrate that the singlet and triplet states have electric-dipole coupling to a common optically excited state. Fast spin relaxation ensures population inversion on the triplet transition when the singlet transition is driven resonantly. By embedding the quantum-dot molecule in a cavity of modest quality factor, a solid-state single-emitter laser could be realized.