Wang Hai-Xiao, Zhan Alan, Xu Ya-Dong, Chen Huan-Yang, You Wen-Long, Majumdar Arka, Jiang Jian-Hua
College of Physics, Optoelectronics and Energy, Collaborative Innovation Center of Suzhou Nano Science and Technology, Soochow University, 1 Shizi Street, Suzhou 215006, People's Republic of China.
J Phys Condens Matter. 2017 Nov 8;29(44):445703. doi: 10.1088/1361-648X/aa8933.
Quantum simulation is a promising approach to understanding complex strongly correlated many-body systems using relatively simple and tractable systems. Photon-based quantum simulators have great advantages due to the possibility of direct measurements of multi-particle correlations and ease of simulating non-equilibrium physics. However, interparticle interaction in existing photonic systems is often too weak, limiting the potential for quantum simulation. Here we propose an approach to enhance the interparticle interaction using exciton-polaritons in MoS monolayer quantum dots embedded in 2D photonic crystal microcavities. Realistic calculation yields optimal repulsive interaction in the range of 1-10 meV-more than an order of magnitude greater than the state-of-the-art value. Such strong repulsive interaction is found to emerge neither in the photon-blockade regime for small quantum dot nor in the polariton-blockade regime for large quantum dot, but in the crossover between the two regimes with a moderate quantum-dot radius around 20 nm. The optimal repulsive interaction is found to be largest in MoS among commonly used optoelectronic materials. Quantum simulation of strongly correlated many-body systems in a finite chain of coupled cavities and its experimental signature are studied via the exact diagonalization of the many-body Hamiltonian. A method to simulate 1D superlattices for interacting exciton-polariton gases in serially coupled cavities is also proposed. Realistic considerations on experimental realizations reveal advantages of transition metal dichalcogenide monolayer quantum dots over conventional semiconductor quantum emitters.
量子模拟是一种很有前景的方法，可利用相对简单且易于处理的系统来理解复杂的强关联多体系统。基于光子的量子模拟器具有很大优势，因为有可能直接测量多粒子关联，并且易于模拟非平衡物理。然而，现有光子系统中的粒子间相互作用往往过弱，限制了量子模拟的潜力。在此，我们提出一种利用嵌入二维光子晶体微腔中的单层二硫化钼量子点中的激子极化激元来增强粒子间相互作用的方法。实际计算得出在1 - 10毫电子伏特范围内的最佳排斥相互作用——比目前的先进值大一个数量级以上。发现这种强排斥相互作用既不出现在小量子点的光子阻塞 regime 中，也不出现在大量子点的极化激元阻塞 regime 中，而是出现在两种 regime 之间的交叉区域，量子点半径约为20纳米时适中。在常用的光电子材料中，发现二硫化钼中的最佳排斥相互作用最大。通过多体哈密顿量的精确对角化，研究了耦合腔有限链中强关联多体系统的量子模拟及其实验特征。还提出了一种在串联耦合腔中模拟相互作用激子极化激元气体的一维超晶格的方法。对实验实现的实际考虑揭示了过渡金属二卤化物单层量子点相对于传统半导体量子发射器的优势。
