论文标题
在较低维
Collisionless sound of bosonic superfluids in lower dimensions
论文作者
论文摘要
低温玻色子的超流体在碰撞方案中已建立。然而，在无碰撞状态中，尚未完全阐明超流体的存在，尤其是在较低的空间维度中。在这里，我们比较了弗拉索夫 - 兰道方程，该方程没有考虑到骨系统的超流量性质与Andreev-Khalatnikov方程，而Andreev-Khalatnikov方程则明确包含超级流速速度。 We show that recent experimental data of the sound mode in a two-dimensional collisionless Bose gas of $^{87}$Rb atoms are in good agreement with both theories but the sound damping is better reproduced by the Andreev -Khalatnikov equations below the Berezinskii-Kosterlitz-Thouless critical temperature $T_c$ while above $T_c$ the Vlasov-Landau results are closer to实验性的。对于一维骨气流体（尚不可用的实验数据），我们发现两种传输理论预测的声速之间的差异更大，并且在这种情况下，也存在超氟化速度的存在会减少声音阻尼。
The superfluidity of low-temperature bosons is well established in the collisional regime. In the collisionless regime, however, the presence of superfluidity is not yet fully clarified, in particular in lower spatial dimensions. Here we compare the Vlasov-Landau equation, which does not take into account the superfluid nature of the bosonic system, with the Andreev-Khalatnikov equations, which instead explicitly contain a superfluid velocity. We show that recent experimental data of the sound mode in a two-dimensional collisionless Bose gas of $^{87}$Rb atoms are in good agreement with both theories but the sound damping is better reproduced by the Andreev -Khalatnikov equations below the Berezinskii-Kosterlitz-Thouless critical temperature $T_c$ while above $T_c$ the Vlasov-Landau results are closer to the experimental ones. For one dimensional bosonic fluids, where experimental data are not yet available, we find larger differences between the sound velocities predicted by the two transport theories and, also in this case, the existence of a superfluid velocity reduces the sound damping.
