Spin conductivity spectrum and spin superfluidity in a binary Bose mixture
Spin conductivity spectrum and spin superfluidity in a binary Bose mixture
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DOI：
10.1103/physrevresearch.5.023058
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发表时间：
2023-01
影响因子：
4.2
通讯作者：
Yuta Sekino;H. Tajima;S. Uchino
中科院分区：
文献类型：
--
作者：
Yuta Sekino;H. Tajima;S. Uchino
研究了具有自旋超流性的两组分玻色-爱因斯坦凝聚体的自旋电导率谱。利用Bogoliubov理论，解析计算了有限交流频率下的自旋电导率和表征δ函数零频率峰的自旋Drude重量。我们表明，频谱表现出幂律行为在低频下，反映了特定的二元BEC的无隙密度和自旋模式。在进入不混溶和量子液滴状态的相变点处，准粒子色散关系的变化修改了幂律。此外，自旋德鲁德重量变得有限，表明零自旋电阻率由于自旋超流性。我们的研究结果还表明，Andreev-Bashkin阻力密度是通过测量自旋电导率谱。
We investigate the spectrum of spin conductivity for a miscible two-component Bose-Einstein condensate (BEC) that exhibits spin superfluidity. By using the Bogoliubov theory, the regular part being the spin conductivity at finite ac frequency and the spin Drude weight characterizing the delta-function peak at zero frequency are analytically computed. We demonstrate that the spectrum exhibits a power-law behavior at low frequency, reflecting gapless density and spin modes specific to the binary BEC. At the phase transition points into immiscible and quantum-droplet states, the change in quasiparticle dispersion relations modifies the power law. In addition, the spin Drude weight becomes finite, indicating zero spin resistivity due to spin superfluidity. Our results also suggest that the Andreev-Bashkin drag density is accessible by measuring the spin conductivity spectrum.