论文标题
在相对论的情况下出现奇数超导性
Appearance of Odd-Frequency Superconductivity in a Relativistic Scenario
论文作者
论文摘要
奇数超导性是一种异国情调的超导状态，其中间隙函数的对称性在频率上是奇数。在这里，我们表明，固有的奇数模式在使用一般频率依赖性间隙函数的洛伦兹变换的应用下，动态出现。为了看到这一点，我们考虑了具有四分之一潜能的狄拉克模型，并执行平均场分析以获得相对论的Bogoliubov-De Gennes系统。求解所得的gor'kov方程可为相对论正常和异常绿色函数提供表达式。选择相对不变的配对项的形式，以使其在非相关性极限下还原为BCS形式。我们在特定框架中选择一个差距函数的ANSATZ，该框架甚至是频率，并分析对相对论框架的促进下异常绿色函数的影响。奇数配对是由于提升而动态出现的。在增强帧中，顺序参数包含均匀且频率奇怪的术语。在Boost参数中，对异常绿色函数的相对论校正在频率上是完全奇怪的。这项工作提供了证据，表明奇数配对可能在相对论超导体中本质上形成。
Odd-frequency superconductivity is an exotic superconducting state in which the symmetry of the gap function is odd in frequency. Here we show that an inherent odd-frequency mode emerges dynamically under application of a Lorentz transformation of the anomalous Green function with the general frequency-dependent gap function. To see this, we consider a Dirac model with quartic potential and perform a mean-field analysis to obtain a relativistic Bogoliubov-de Gennes system. Solving the resulting Gor'kov equations yields expressions for relativistic normal and anomalous Green functions. The form of the relativistically invariant pairing term is chosen such that it reduces to BCS form in the non-relativistic limit. We choose an ansatz for the gap function in a particular frame which is even-frequency and analyze the effects on the anomalous Green function under a boost into a relativistic frame. The odd-frequency pairing emerges dynamically as a result of the boost. In the boosted frame the order parameter contains terms which are both even and odd in frequency. The relativistic correction to the anomalous Green function to first order in the boost parameter is completely odd in frequency. This work provides evidence that odd-frequency pairing may form intrinsically within relativistic superconductors.
