论文标题
超导量子位的理论超出了集体元素近似值
Theory of superconducting qubits beyond the lumped element approximation
论文作者
论文摘要
在对超导码头和相关设备的设计和调查中，总元素电路模型是标准理论方法。但是，许多重要的物理问题超出了其范围，例如具有强大的约瑟夫森连接的电路的行为，具有大量电流和小型超导装置的特性。通过对Bogoliubov-De Gennes方程的自洽解决方案进行仪表转换，我们在这里开发了一种形式主义，该形式主义非扰动地对待Josephson耦合。我们将形式主义应用于（a）表明费米海的效应可以有助于小电荷量子的有效电容； （b）在小rf鱿鱼量子尺中表现出顺时针和逆时针电流状态的不对称性； （c）提供了适用于计算纠缠电子数量的超导Schrodinger猫的显微镜波函数。
In the design and investigation of superconducting qubits and related devices, a lumped element circuit model is the standard theoretical approach. However, many important physical questions lie beyond its scope, e.g. the behavior of circuits with strong Josephson junctions carrying substantial currents and the properties of small superconducting devices. By performing gauge transformations on self-consistent solutions of the Bogoliubov-de Gennes equations, we develop here a formalism that treats Josephson couplings non-perturbatively. We apply the formalism to (a) show that Fermi sea effects can contribute to the effective capacitance of small charge qubits; (b) demonstrate an asymmetry in clockwise and counterclockwise current states in small RF squid qubits; and (c) provide a microscopic wavefunction of superconducting Schrodinger cats suitable for computing the number of entangled electrons.
