Shishkov Vladislav Yu, Andrianov Evgeny S, Zasedatelev Anton V, Lagoudakis Pavlos G, Lozovik Yurii E
Dukhov Research Institute of Automatics (VNIIA), 22 Sushchevskaya, Moscow 127055, Russia; Moscow Institute of Physics and Technology, 9 Institutskiy pereulok, Dolgoprudny 141700, Moscow region, Russia; and Hybrid Photonics Laboratory, Skolkovo Institute of Science and Technology, Territory of Innovation Center Skolkovo, Bolshoy Boulevard 30, building 1, 121205 Moscow, Russia.
Hybrid Photonics Laboratory, Skolkovo Institute of Science and Technology, Territory of Innovation Center Skolkovo, Bolshoy Boulevard 30, building 1, 121205 Moscow, Russia.
Phys Rev Lett. 2022 Feb 11;128(6):065301. doi: 10.1103/PhysRevLett.128.065301.
In this Letter, we give an analytical quantum description of a nonequilibrium polariton Bose-Einstein condensate (BEC) based on the solution of the master equation for the full polariton density matrix in the limit of fast thermalization. We find the density matrix of a nonequilibrium BEC, that takes into account quantum correlations between all polariton states. We show that the formation of BEC is accompanied by the build-up of cross-correlations between the ground state and the excited states reaching their highest values at the condensation threshold. Despite the nonequilibrium nature of polariton systems, we show the average population of polariton states exhibits the Bose-Einstein distribution with an almost zero effective chemical potential above the condensation threshold similar to an equilibrium BEC. We demonstrate that above threshold the effective temperature of polaritons drops below the reservoir temperature.
在本信函中，我们基于快速热化极限下全极化激元密度矩阵的主方程解，给出了非平衡极化激元玻色 - 爱因斯坦凝聚体（BEC）的解析量子描述。我们找到了非平衡BEC的密度矩阵，该矩阵考虑了所有极化激元态之间的量子关联。我们表明，BEC的形成伴随着基态与激发态之间交叉关联的建立，这些交叉关联在凝聚阈值处达到最大值。尽管极化激元系统具有非平衡性质，但我们表明，极化激元态的平均占据数呈现玻色 - 爱因斯坦分布，在凝聚阈值以上有效化学势几乎为零，这与平衡BEC相似。我们证明，在阈值以上，极化激元的有效温度降至低于库温度。
