arXiv subjects

Wen-An Li

Publications and source records attributed to Wen-An Li.

4 recordsLinked to original sources

arXiv2019

Tunable photon blockade in a whispering-gallery-mode microresonator coupled with two nanoparticles

We have theoretically studied the photon statistical properties in a nonlinear whispering-gallery-mode microresonator coupled with two nanoparticles. By tuning the relative position of two nanoparticles, the photon statistical features of the system can be modified remarkably. Interestingly, a controllable switching between unconventional and conventional photon blockade can be realized by manipulating the angular positions of two nanoparticles. We also investigate the influence of the Kerr effect on the second order correlation function and find that there is an optimal choice for the relative position of two nanoparticles and the strength of Kerr effect that can generate strong antibunching. Furthermore, under the strong driving, two photon blockade can be achieved when the system is close to an exceptional point. Our work may provide an effective way to control photon statistical characteristics and have potential applications in quantum information science.

quant-ph↗

arXiv2019

Enhancement of optomechanically induced sum sideband using parametric interactions

We theoretically study radiation pressure induced generation of the frequency components at the sum sideband in an optomechanical system containing an optical parametric amplifier (OPA). It is shown that an OPA inside a cavity can considerably enhance the amplitude of sum sideband even with low power input fields. We find a new matching condition for the upper sum sideband generation. The height and width of the new peak can be adjusted by the nonlinear gain of the OPA. Furthermore, the lower sum sideband generation can be enhanced with several orders of magnitude by tuning the nonlinear gain parameter and the phase of the field pumping the OPA. The enhanced sum sideband may have potential applications to the manipulation of light in a on-chip optomechanical device and the sensitively sensing for precision measurement in the weak optomechanical coupling regime.

physics.optics↗

arXiv2017

Simplify proposal for realizing multiqubit tunable phase gate in circuit QED

We propose a scheme to realize a multiqubit tunable phase gate in a circuit QED setup where two resonators, each coupling with a qudit, are interconnected to a common qudit (d=4). In this proposal, only two levels of each qudit serve as the logical states and the other two levels are used for the gate realization. The proposal is efficient and simple because only a classical microwave pulse is needed, no matter how many qudits are involved, which significantly reduces experimental difficulty. In a nonresonant case, the tunable phase gate can be achieved readily, while under the resonant condition, a π-phase gate can be realized after a full cycle of Rabi oscillation where the gate speed is rather fast due to the resonant interaction. We have shown that the resulting effective dynamics allows for the creation of a high-fidelity phase gate. The influence of various decoherence processes such as the decay of the resonator mode and the relaxation of the qudits is investigated. Moreover, the proposed scheme can be easily generalized to realize N-qubit phase gate.

quant-ph↗

arXiv2012

Controllable entanglement preparations between atoms in spatially-separated cavities via quantum Zeno dynamics

By using quantum Zeno dynamics, we propose a controllable approach to deterministically generate tripartite GHZ states for three atoms trapped in spatially separated cavities. The nearest-neighbored cavities are connected via optical fibers and the atoms trapped in two ends are tunably driven. The generation of the GHZ state can be implemented by only one step manipulation, and the EPR entanglement between the atoms in two ends can be further realized deterministically by Von Neumann measurement on the middle atom. Note that the duration of the quantum Zeno dynamics is controllable by switching on/off the applied external classical drivings and the desirable tripartite GHZ state will no longer evolve once it is generated. The robustness of the proposal is numerically demonstrated by considering various decoherence factors, including atomic spontaneous emissions, cavity decays and fiber photon leakages, etc. Our proposal can be directly generalized to generate multipartite entanglement by still driving the atoms in two ends.

quant-ph↗