Dissipative Landau-Zener transitions of a qubit: Bath-specific and universal behavior
Dissipative Landau-Zener transitions of a qubit: Bath-specific and universal behavior
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DOI：
10.1103/physrevb.75.214308
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发表时间：
2007-03
影响因子：
3.7
通讯作者：
Keiji Saito;M. Wubs;S. Kohler;Y. Kayanuma;P. Hānggi
中科院分区：
文献类型：
--
作者：
Keiji Saito;M. Wubs;S. Kohler;Y. Kayanuma;P. Hānggi
我们研究与零温浴耦合的量子位中的朗道-齐纳跃迁。推导了适用于非简并基态模型的通用公式。我们计算与玻色子或旋转浴耦合的量子位的精确跃迁概率。浴和量子位浴耦合的性质反映在转移概率中。对于对角耦合，当浴引起非绝热量子位态的能量波动但它们之间没有跃迁时，跃迁概率与孤立量子位的标准朗道-齐纳概率一致。这个结果是通用的，因为它不依赖于特定的浴槽类型。相比之下，对于纯非对角线耦合，隧道概率对耦合强度敏感。我们讨论了我们的结果与分子纳米磁体实验、电路 QED 以及超导相位量子位的快速脉冲读出的相关性。
We study Landau-Zener transitions in a qubit coupled to a bath at zero temperature. A general formula that is applicable to models with a nondegenerate ground state is derived. We calculate exact transition probabilities for a qubit coupled to either a bosonic or a spin bath. The nature of the baths and the qubit-bath coupling is reflected in the transition probabilities. For diagonal coupling, when the bath causes energy fluctuations of the diabatic qubit states but no transitions between them, the transition probability coincides with the standard Landau-Zener probability of an isolated qubit. This result is universal as it does not depend on the specific type of bath. For pure off-diagonal coupling, by contrast, the tunneling probability is sensitive to the coupling strength. We discuss the relevance of our results for experiments on molecular nanomagnets, in circuit QED, and for the fast-pulse readout of superconducting phase qubits.