Tighineanu Petru, Daveau Raphaël S, Lehmann Tau B, Beere Harvey E, Ritchie David A, Lodahl Peter, Stobbe Søren
Niels Bohr Institute, University of Copenhagen, Blegdamsvej 17, DK-2100 Copenhagen, Denmark.
Cavendish Laboratory, University of Cambridge, J. J. Thomson Avenue, CB3 0HE Cambridge, United Kingdom.
Phys Rev Lett. 2016 Apr 22;116(16):163604. doi: 10.1103/PhysRevLett.116.163604. Epub 2016 Apr 21.
We report on the observation of single-photon superradiance from an exciton in a semiconductor quantum dot. The confinement by the quantum dot is strong enough for it to mimic a two-level atom, yet sufficiently weak to ensure superradiance. The electrostatic interaction between the electron and the hole comprising the exciton gives rise to an anharmonic spectrum, which we exploit to prepare the superradiant quantum state deterministically with a laser pulse. We observe a fivefold enhancement of the oscillator strength compared to conventional quantum dots. The enhancement is limited by the base temperature of our cryostat and may lead to oscillator strengths above 1000 from a single quantum emitter at optical frequencies.
我们报告了在半导体量子点中对激子单光子超辐射的观测结果。量子点的限制作用足够强，使其能够模拟二能级原子，但又足够弱以确保超辐射。构成激子的电子和空穴之间的静电相互作用产生了非谐光谱，我们利用这一光谱通过激光脉冲确定性地制备超辐射量子态。与传统量子点相比，我们观测到振子强度提高了五倍。这种增强受到我们低温恒温器基础温度的限制，并且在光频率下，单个量子发射体可能会导致振子强度超过1000。
