We investigate a circular cavity billiard within which a pair of identical hard disks of smaller but finite size is confined. Each disk shows a free motion except when bouncing elastically with its partner and with the boundary wall. Despite its circular symmetry, this system is nonintegrable and almost chaotic because of the (short-range) interaction between the disks. We quantize the system by incorporating the excluded volume effect for the wavefunction. Eigenvalues and eigenfunctions are obtained by tuning the relative size between the disks and the billiard. We define the volume V of the cavity and the pressure P, i.e., the derivative of each eigenvalue with respect to V. Reflecting the fact that the energy spectra of eigenvalues versus the disk size show a multitude of level repulsions, P-V characteristics shows the anomalous fluctuations accompanied by many van der Waals-like peaks in each of individual excited eigenstates taken as a quasi-equilibrium. For each eigenstate, we calculate the expectation values of the square distance between two disks, and point out their relationship with the pressure fluctuations.
Optimization of circular cavities via guided-mode expansion method based inverse design
NC State University（北卡罗来纳州立大学）；University of Maryland（马里兰大学）；Institute of Research in Electronics and Applied Physics（电子与应用物理研究所）；Joint Quantum Institute（联合量子研究所）
Demonstration of traveling-wave interactions between spontaneous photon emissions and atoms in a chiral F-P cavity
State Key Laboratory of Quantum Optics and Quantum Optics Devices, Institute of Opto-Electronics, Shanxi University（山西大学光电研究所量子光学与量子光学器件国家重点实验室）；Collaborative Innovation Center of Extreme Optics, Shanxi University（山西大学极端光学协同创新中心）
Benchmarking maximum-likelihood state estimation with an entangled two-cavity state
在[P.Six等人，Phys. Rev. A 93，012109（2016）]在由圆形里德伯原子纠缠的两个微波腔的非局域态上实验实现。我们使用长序列的测量共振和色散探针原子在涉及系统退相干的时间尺度上提供的信息。此外，在同一重建中，我们受益于提供互补信息的不同测量协议的合并。最后，我们得到了重建密度算子的矩阵元素的实际误差条。这些结果证明了该方法的针对性和精确性，可直接应用于任何复杂的量子系统。
Tunable-Size Unruh-DeWitt Detector in a Multimode Cavity
Institut für Theoretische Physik, Universität Innsbruck（因斯布鲁克大学理论物理研究所）；Institute for Quantum Optics and Quantum Information, Austrian Academy of Sciences（奥地利科学院量子光学与量子信息研究所）；Okinawa Institute of Science and Technology Graduate University（冲绳科学技术大学院大学）；Institute of Physics, Maria Curie-Skłodowska University（玛丽亚·居里-斯克沃多夫斯卡大学物理研究所）
