scholarly journals Quantum dynamics of a microwave driven superconducting phase qubit coupled to a two-level system

2010 ◽  
Vol 82 (13) ◽  
Author(s):  
Guozhu Sun ◽  
Xueda Wen ◽  
Bo Mao ◽  
Zhongyuan Zhou ◽  
Yang Yu ◽  
...  
Keyword(s):  
Quantum Dynamics ◽  
Superconducting Phase ◽  
Level System ◽  
Phase Qubit

scholarly journals Entanglement Research for the Coupled Superconducting Phase Qubit and a Two-Level System

2020 ◽  
Vol 2020 ◽  
pp. 1-8
Author(s):  
Jianxin Shi
Keyword(s):  
Sudden Death ◽  
Quantum Dynamics ◽  
Coupling Effect ◽  
Superconducting Devices ◽  
Superconducting Phase ◽  
Level System ◽  
Superconducting Qubit ◽  
Driving Time ◽  
Initial States ◽  
Phase Qubit

Entanglement can exist not only in the microscopic system (e.g., atom, photon, and ion trap) but also in macroscopic systems. According to recent research, entanglement can be achieved and controlled in superconducting devices. The quantum dynamics and entanglement mechanism of the coupled superconducting phase qubit and a two-level system (TLS) were demonstrated when the bipartite system was under microwave driving. Besides, the results reveal that when the system was experiencing decoherence, entanglement (concurrence) of the coupled superconducting phase qubit and TLS would oscillate damply with microwave driving time, even exhibiting concurrence sudden death and revival. The coupling effect of the superconducting qubit and TLS system and the resonant microwave together help to achieve entanglement, while concurrence death and concurrence revival are dependent on the decoherence source and mechanism, for example, the resonant microwave driving time acting on the bipartite coupling system. Furthermore, the simulation results show the entanglement of the coupled qubit and TLS system also depends on the purity of the initial states of the system. The article carried out a numerical simulation on the entanglement of different initial states, and the results showed that the entanglement of the coupled system changes with different initial states. For different initial states, entanglement, sudden death, and rejuvenation are still visible.

Spectrum of a superconducting phase qubit coupled to a microscopic two-level system

2014 ◽  
Vol 59 (29-30) ◽  
pp. 3835-3840 ◽  
Author(s):  
Zhican Du ◽  
Xueda Wen ◽  
Yu Zhou ◽  
Guozhu Sun ◽  
Jian Chen ◽  
...  
Keyword(s):  
Superconducting Phase ◽  
Level System ◽  
Phase Qubit

scholarly journals Entanglement dynamics of a superconducting phase qubit coupled to a two-level system

2012 ◽  
Vol 86 (6) ◽  
Author(s):  
Guozhu Sun ◽  
Zhongyuan Zhou ◽  
Bo Mao ◽  
Xueda Wen ◽  
Peiheng Wu ◽  
...  
Keyword(s):  
Superconducting Phase ◽  
Entanglement Dynamics ◽  
Level System ◽  
Phase Qubit

scholarly journals Observation and quantification of the quantum dynamics of a strong-field excited multi-level system

2017 ◽  
Vol 7 (1) ◽  
Author(s):  
Zuoye Liu ◽  
Quanjun Wang ◽  
Jingjie Ding ◽  
Stefano M. Cavaletto ◽  
Thomas Pfeifer ◽  
...  
Keyword(s):  
Quantum Dynamics ◽  
Strong Field ◽  
Level System ◽  
Multi Level

scholarly journals Thermal inclusions: how one spin can destroy a many-body localized phase

2017 ◽  
Vol 375 (2108) ◽  
pp. 20160428 ◽  
Author(s):  
Pedro Ponte ◽  
C. R. Laumann ◽  
David A. Huse ◽  
A. Chandran
Keyword(s):  
Random Fields ◽  
Quantum Dynamics ◽  
Quantum Systems ◽  
Spin Model ◽  
Single Site ◽  
Level System ◽  
Many Body ◽  
Discontinuous Transition ◽  
Logarithmic Corrections ◽  
Basic Features

Many-body localized (MBL) systems lie outside the framework of statistical mechanics, as they fail to equilibrate under their own quantum dynamics. Even basic features of MBL systems, such as their stability to thermal inclusions and the nature of the dynamical transition to thermalizing behaviour, remain poorly understood. We study a simple central spin model to address these questions: a two-level system interacting with strength J with N ≫1 localized bits subject to random fields. On increasing J , the system transitions from an MBL to a delocalized phase on the vanishing scale J c ( N )∼1/ N , up to logarithmic corrections. In the transition region, the single-site eigenstate entanglement entropies exhibit bimodal distributions, so that localized bits are either ‘on’ (strongly entangled) or ‘off’ (weakly entangled) in eigenstates. The clusters of ‘on’ bits vary significantly between eigenstates of the same sample, which provides evidence for a heterogeneous discontinuous transition out of the localized phase in single-site observables. We obtain these results by perturbative mapping to bond percolation on the hypercube at small J and by numerical exact diagonalization of the full many-body system. Our results support the arguments that the MBL phase is unstable in systems with short-range interactions and quenched randomness in dimensions d that are high but finite. This article is part of the themed issue ‘Breakdown of ergodicity in quantum systems: from solids to synthetic matter’.

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