论文标题
量子临界金属中的奇数配对
Odd frequency pairing in a quantum critical metal
论文作者
论文摘要
我们分析了金属中量子临界点（QCP）附近奇数配对的可能性。我们考虑一个具有动态配对交互的模型$ V（ω_n）\ sim 1/|ω_n|^γ$（$γ$ -MODEL）。这种相互作用会在正常状态下引起非Fermi液体，并且对配对很有吸引力。这两个趋势相互竞争。我们为配对差距$δ（ω_m）=-δ（ω_m）$搜索奇数解决方案。我们表明，对于$γ<1 $，奇数频率超导性会通过非fermi液体失去竞争，但不会发展。我们表明，配对确实在扩展模型中发展，在扩展模型中，配对通道中的相互作用大于粒子孔通道中的相互作用。对于$γ> 1 $，我们认为原始模型是朝着奇数配对的边界，并详细分析了如何通过小的外部扰动触发超导性。此外，我们表明，对于$γ> 2 $，该系统在参数空间中有限范围内的临界点被冷冻。这引起了具有平坦区域的高度非常规相图。
We analyze a possibility for odd-frequency pairing near a quantum critical point(QCP) in a metal. We consider a model with dynamical pairing interaction $V(Ω_n)\sim 1/|Ω_n|^γ$ (the $γ$-model). This interaction gives rise to a non-Fermi liquid in the normal state and is attractive for pairing. The two trends compete with each other. We search for odd-frequency solutions for the pairing gap $Δ(ω_m)= -Δ(ω_m)$. We show that for $γ<1$, odd-frequency superconductivity looses the competition with a non-Fermi liquid and does not develop. We show that the pairing does develop in the extended model in which interaction in the pairing channel is larger than the one in the particle-hole channel. For $γ>1$, we argue that the original model is at the boundary towards odd-frequency pairing and analyze in detail how superconductivity is triggered by a small external perturbation. In addition, we show that for $γ>2$, the system gets frozen at the critical point towards pairing in a finite range in the parameter space. This give rise to highly unconventional phase diagrams with flat regions.
