Huang Boning, Ke Yongguan, Zhong Honghua, Kivshar Yuri S, Lee Chaohong
Institute of Quantum Precision Measurement, State Key Laboratory of Radio Frequency Heterogeneous Integration, College of Physics and Optoelectronic Engineering, <a href="https://ror.org/01vy4gh70">Shenzhen University</a>, Shenzhen 518060, China.
Laboratory of Quantum Engineering and Quantum Metrology, School of Physics and Astronomy, <a href="https://ror.org/0064kty71">Sun Yat-Sen University (Zhuhai Campus)</a>, Zhuhai 519082, China.
Phys Rev Lett. 2024 Oct 4;133(14):140202. doi: 10.1103/PhysRevLett.133.140202.
Bound states in the continuum (BICs) are localized modes residing in the radiation continuum. They were first predicted for single-particle states, and became a general feature of many wave systems. In many-body quantum physics, it is still unclear what would be a close analog of BICs, and whether interparticle interaction may induce BICs. Here, we predict a novel type of multiparticle states in the interaction-modulated Bose-Hubbard model that can be associated with the BIC concept. Under periodic boundary conditions, a so-called quasi-BIC appears as a bound pair residing in a standing wave formed by the third particle. Under open boundary conditions, such a hybrid state becomes an eigenstate of the system. We demonstrate that the Thouless pumping of the quasi-BICs can be realized by modulating the onsite interactions in space and time. Surprisingly, while the center of mass of the quasi-BIC is shifted by a unit cell in one cycle, the bound pair moves in the opposite direction with the standing wave.
连续统中的束缚态（BICs）是存在于辐射连续统中的局域模式。它们最初是针对单粒子态预测的，并成为许多波动系统的一个普遍特征。在多体量子物理学中，目前仍不清楚BICs的紧密类似物是什么，以及粒子间相互作用是否会诱导出BICs。在此，我们在相互作用调制的玻色 - 哈伯德模型中预测了一种新型的多粒子态，它可与BIC概念相关联。在周期性边界条件下，一种所谓的准BIC作为一个束缚对出现在由第三个粒子形成的驻波中。在开放边界条件下，这样的混合态成为系统的本征态。我们证明，通过在空间和时间上调制在位相互作用，可以实现准BICs的 Thouless 泵浦。令人惊讶的是，虽然准BIC的质心在一个周期内移动一个晶胞，但束缚对与驻波沿相反方向移动。
