The Institute of Mathematical Sciences, Chennai 600113, India.
Phys Rev Lett. 2009 Dec 4;103(23):230403. doi: 10.1103/PhysRevLett.103.230403.
We study solitary wave propagation in the condensate of a system of hard-core bosons with nearest-neighbor interactions. For this strongly repulsive system, the evolution equation for the condensate order parameter of the system, obtained using spin-coherent state averages, is different from the usual Gross-Pitaevskii equation (GPE). The system is found to support two kinds of solitons when there is a particle-hole imbalance: a dark soliton that dies out as the velocity approaches the sound velocity and a new type of soliton which brightens and persists all the way up to the sound velocity, transforming into a periodic wave train at supersonic speed. Analogous to the GPE soliton, the energy-momentum dispersion for both solitons is characterized by Lieb II modes.
我们研究了具有最近邻相互作用的硬芯玻色子系统中的孤立波传播。对于这个强排斥系统，使用自旋相干态平均值得到的系统凝聚态序参量的演化方程与通常的 Gross-Pitaevskii 方程（GPE）不同。当存在粒子-空穴不平衡时，系统被发现支持两种孤子：一种暗孤子，当速度接近声速时会消失，另一种新的孤子，它会变亮并一直持续到声速，在超音速下转化为周期性波列。类似于 GPE 孤子，两种孤子的能量-动量色散都具有 Lieb II 模式。
