论文标题
平均时间对称系统中具有动量依赖性增益和损失的假想自旋轨道耦合
Imaginary spin-orbital coupling in parity-time symmetric systems with momentum-dependent gain and loss
论文作者
论文摘要
旋转轨道耦合（SOC）和平等时代（$ \ Mathcal {pt} $）对称性都吸引了对凝聚态物理学，冷原子物理，光学和声学的最重要研究兴趣，以开发自旋旋转，量子量，量子计算，精确的传感器和新功能。自然SOC是一种内在的相对论效应。但是，如今对合成的SOC越来越兴趣。在这里，我们表明，在$ \ Mathcal {pt} $ - 对称旋转1/2系统中，动量依赖的平衡增益和损失可以综合一种新型的SOC，我们称之为虚构的SOC。假想的SOC可以实质上改变系统的能量谱。首先，我们证明它可以通过双门结构生成纯真实的能源谱。因此，它具有生成超固体条纹状态的能力。特别是，虚构的Soc条纹状态可能具有很高的对比度。此外，假想的SOC还可以通过可调的复杂能带产生一个频谱，其中波是放大或腐烂的。因此，假想的SOC还将在$ \ Mathcal {pt} $ - 基于对称的相干波放大器/吸收器的工程中找到应用。想象中的SOC的潜在实验实现是在冷原子气体和由非本地增益和损失构成的耦合波导系统中提出的。
Spin-orbital coupling (SOC) and parity-time ($\mathcal{PT}$) symmetry both have attracted paramount research interest in condensed matter physics, cold atom physics, optics and acoustics to develop spintronics, quantum computation, precise sensors and novel functionalities. Natural SOC is an intrinsic relativistic effect. However, there is an increasing interest in synthesized SOC nowadays. Here, we show that in a $\mathcal{PT}$-symmetric spin-1/2 system, the momentum-dependent balanced gain and loss can synthesize a new type of SOC, which we call imaginary SOC. The imaginary SOC can substantially change the energy spectrum of the system. Firstly, we show that it can generate a pure real energy spectrum with a double-valleys structure. Therefore, it has the ability to generate supersolid stripe states. Especially, the imaginary SOC stripe state can have a high contrast of one. Moreover, the imaginary SOC can also generate a spectrum with tunable complex energy band, in which the waves are either amplifying or decaying. Thus, the imaginary SOC would also find applications in the engineering of $\mathcal{PT}$-symmetry-based coherent wave amplifiers/absorbers. Potential experimental realizations of imaginary SOC are proposed in cold atomic gases and systems of coupled waveguides constituted of nonlocal gain and loss.
