Based on the quantum Zeno dynamics,we propose a two-qubit non-geometric conditional phase gate between two nitrogen-vacancy centers coupled to a whispering-gallery mode cavity.The varying phases design of periodic las...Based on the quantum Zeno dynamics,we propose a two-qubit non-geometric conditional phase gate between two nitrogen-vacancy centers coupled to a whispering-gallery mode cavity.The varying phases design of periodic laser can be used for realizing non-geometric conditional phase gate,and the cavity mode is virtually excited during the gate operation.Thus,the fidelity of the gate operation is insensitive to cavity decay and the fluctuation of the preset laser intensity.The numerical simulation with a realistic set of experimental parameters shows that the gate fidelity 0.987 can be within reached in the near future.展开更多
The study of the polaron of an open quantum system plays an important role in verifying the effectiveness of an approximate many-body theory and predicting novel quantum phenomena in open quantum systems. In a pioneer...The study of the polaron of an open quantum system plays an important role in verifying the effectiveness of an approximate many-body theory and predicting novel quantum phenomena in open quantum systems. In a pioneering work, Piazza et al.(2021) proposed a Fermi-polaron scheme with a lossy impurity, which exhibits a novel long-lived attractive polaron branch in the quantum Zeno limit. However, we have encountered a counterpart problem in which an impurity interacting with an open quantum bath scatters exciting polarons, which is what we focus on. In this work, we determine through analytical research the molecular state under the two limits of vanishingly small and infinitely large dissipation intensities as well as the reason why the dissipation range leads to a decrease in the gap between the molecular state and the molecule-hole continuum in the former case.The spectrum functions of molecular and polaron states with different dissipation ranges and loss rates are investigated. We find the spectral signals of molecular and polaron states will first diffuse and then revive as the dissipation increases. Moreover, we show that the attractive and repulsive polarons respond differently to an increasing dissipation range in our model. Finally, we exhibit the polaron energy, residue, effective mass, and two-body decay for mass-balanced and imbalanced systems. Our results might be useful for cold-atom experiments on open quantum systems.展开更多
基金Supported by the National Fundamental Research Program under Grant No. 2012CB921601National Natural Science Foundation of China under Grant No. 10974028+1 种基金the Doctoral Foundation of the Ministry of Education of China under Grant No. 20093514110009the Natural Science Foundation of Fujian Province under Grant No. 2009J06002
文摘Based on the quantum Zeno dynamics,we propose a two-qubit non-geometric conditional phase gate between two nitrogen-vacancy centers coupled to a whispering-gallery mode cavity.The varying phases design of periodic laser can be used for realizing non-geometric conditional phase gate,and the cavity mode is virtually excited during the gate operation.Thus,the fidelity of the gate operation is insensitive to cavity decay and the fluctuation of the preset laser intensity.The numerical simulation with a realistic set of experimental parameters shows that the gate fidelity 0.987 can be within reached in the near future.
基金supported by the National Natural Science Foundation of China (Grant Nos. 11704029, and 12174024)supported by the National Natural Science Foundation of China (Grant No. 11504038)。
文摘The study of the polaron of an open quantum system plays an important role in verifying the effectiveness of an approximate many-body theory and predicting novel quantum phenomena in open quantum systems. In a pioneering work, Piazza et al.(2021) proposed a Fermi-polaron scheme with a lossy impurity, which exhibits a novel long-lived attractive polaron branch in the quantum Zeno limit. However, we have encountered a counterpart problem in which an impurity interacting with an open quantum bath scatters exciting polarons, which is what we focus on. In this work, we determine through analytical research the molecular state under the two limits of vanishingly small and infinitely large dissipation intensities as well as the reason why the dissipation range leads to a decrease in the gap between the molecular state and the molecule-hole continuum in the former case.The spectrum functions of molecular and polaron states with different dissipation ranges and loss rates are investigated. We find the spectral signals of molecular and polaron states will first diffuse and then revive as the dissipation increases. Moreover, we show that the attractive and repulsive polarons respond differently to an increasing dissipation range in our model. Finally, we exhibit the polaron energy, residue, effective mass, and two-body decay for mass-balanced and imbalanced systems. Our results might be useful for cold-atom experiments on open quantum systems.
