论文标题
两组分玻色的凝结物中的类似鹰辐射和量子纠缠：散发的激发
Analogous Hawking radiation and quantum entanglement in two-component Bose-Einstein condensates: the gapped excitations
论文作者
论文摘要
在可调二进制的二元玻色凝结物凝结物系统中，在零温度下的冷原子的冷凝物通过原子超细状态之间的兔过渡研究了该系统可以通过耦合的两体无间隙激励模型来表示，并进行了刺激。我们在伸长的两个组分子玻色 - 因子凝结物中设置了超音速和亚音速方向的配置，它们之间的声学范围尤其是由于刺激的刺激而试图模仿鹰的辐射。在亚音音 - 苏联传输的过渡中采用了简化的阶梯式声速变化，因此可以在分析上可以治疗模型。间隙激发的分散性关系中的有效能差术语引入了亚音速级中的阈值频率$ω__\ text {min} $，在下面不存在传播模式。因此，由于修改的灰色因子，鹰型模式的粒子光谱显着偏离阈值频率附近的无间隙案例，随着模式频率低于$ω__\ text {min} $，它消失了。根据Peres-Horodecki-Simon（PHS）标准，还研究了霍金模式的量子纠缠及其合作伙伴的影响。已经发现，当对模式的频率尤其约为$ω\ simω__\ text {min} $时，散布激发的存在将使无间隙激发的对量子变质。最重要的是，当无间隙和间隙激发之间的耦合常数变得足够大时，小$ω$制度中散发激发的巨大粒子密度将大大消除无间隙激发的一对模式。将讨论详细的时间依赖性PHS标准。
The condensates of cold atoms at zero temperature in the tunable binary Bose-Einstein condensate system are studied with the Rabi transition between atomic hyperfine states where the system can be represented by a coupled two-field model of gapless excitations and gapped excitations. We set up the configuration of the supersonic and subsonic regimes with the acoustic horizon between them in the elongated two-component Bose-Einstein condensates, trying to mimic Hawking radiations, in particular due to the gapped excitations. The simplified step-like sound speed change is adopted for the subsonic-supersonic transition so that the model can be analytically treatable. The effective energy gap term in the dispersion relation of the gapped excitations introduces the threshold frequency $ω_\text{min}$ in the subsonic regime, below which the propagating modes do not exist. Thus, the particle spectrum of the Hawking modes significantly deviates from that of the gapless cases near the threshold frequency due to the modified grey-body factor, which vanishes as the mode frequency is below $ω_\text{min}$. The influence from the gapped excitations to the quantum entanglement of the Hawking mode and its partner of the gapless excitations is also studied according to the Peres-Horodecki-Simon (PHS) criterion. It is found that the presence of the gapped excitations will deteriorate the quantumness of the pair modes of the gapless excitations when the frequency of the pair modes in particular is around $ω\sim ω_\text{min}$. On top of that, when the coupling constant between the gapless and gapped excitations becomes large enough, the huge particle density of the gapped excitations in the small $ω$ regime will significantly disentangle the pair modes of the gapless excitations. The detailed time-dependent PHS criterion will be discussed.
