Braumüller Jochen, Marthaler Michael, Schneider Andre, Stehli Alexander, Rotzinger Hannes, Weides Martin, Ustinov Alexey V
Physikalisches Institut, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, 76131, Karlsruhe, Germany.
Institut für Theoretische Festkörperphysik, Karlsruhe Institute of Technology, Wolfgang-Gaede-Straße 1, 76131, Karlsruhe, Germany.
Nat Commun. 2017 Oct 3;8(1):779. doi: 10.1038/s41467-017-00894-w.
The quantum Rabi model describes the fundamental mechanism of light-matter interaction. It consists of a two-level atom or qubit coupled to a quantized harmonic mode via a transversal interaction. In the weak coupling regime, it reduces to the well-known Jaynes-Cummings model by applying a rotating wave approximation. The rotating wave approximation breaks down in the ultra-strong coupling regime, where the effective coupling strength g is comparable to the energy ω of the bosonic mode, and remarkable features in the system dynamics are revealed. Here we demonstrate an analog quantum simulation of an effective quantum Rabi model in the ultra-strong coupling regime, achieving a relative coupling ratio of g/ω ~ 0.6. The quantum hardware of the simulator is a superconducting circuit embedded in a cQED setup. We observe fast and periodic quantum state collapses and revivals of the initial qubit state, being the most distinct signature of the synthesized model.An analog quantum simulation scheme has been explored with a quantum hardware based on a superconducting circuit. Here the authors investigate the time evolution of the quantum Rabi model at ultra-strong coupling conditions, which is synthesized by slowing down the system dynamics in an effective frame.
量子拉比模型描述了光与物质相互作用的基本机制。它由一个两能级原子或量子比特通过横向相互作用与一个量子化的谐振模式耦合而成。在弱耦合 regime 下，通过应用旋转波近似，它简化为著名的 Jaynes-Cummings 模型。在超强耦合 regime 中，旋转波近似失效，此时有效耦合强度 g 与玻色子模式的能量 ω 相当，系统动力学中会展现出显著特征。在此，我们展示了在超强耦合 regime 下有效量子拉比模型的模拟量子模拟，实现了 g/ω 约为 0.6 的相对耦合比。模拟器的量子硬件是嵌入在腔量子电动力学设置中的超导电路。我们观察到初始量子比特态的快速且周期性的量子态坍缩和复苏，这是合成模型最显著的特征。一种模拟量子模拟方案已基于超导电路的量子硬件进行了探索。在此，作者研究了在超强耦合条件下量子拉比模型的时间演化，该模型是通过在有效框架中减缓系统动力学而合成的。
