Personal Information and education

 

I was born in 1989, and received a bachelor degree in Electrical Engineering (Xi’an Jiaotong University) in 2012. I chose quantum optics and quantum information as my postgraduate research topic.

 

In 2012-2017, I studied in the department of Applied Physics as a Ph.D. student. My thesis topic was “Quantum Dynamics in Hybrid Quantum Circuit System With Longitudinal Coupling”. During 2015-2016, I studied in RIKEN, Japan [under the supervision of Prof. Franco Nori] as an international Ph.D.-joint student. In September 2017, I received my Ph.D. degree. During 2019-2020, I am a Post-Doc researcher at RIKEN (Japan).

 

Currently I am an associate professor in XJTU (China).

 

Research topics

In 2017, I started my lecturer position in the physics department of Xi'an Jiaotong University.
My research now is about quantum control based on hybrid superconducting quantum circuits (SQC) systems. By considering coupling SQC with other artificial quantum plateforms, such as nanomechanical oscillators, surface acoustic waves (SAW) and various types of color-centers, better quantum controls applications could be realized. My present and future reseach topics include: 
1. Engineering phonons at the single-quantum level:
Mechanical quanta (phonons) can exist in a localized mechanical resonator, phonons SAW cavity or a travelling acoustic wave. Manipulating phonons in quantum level has attracted considerable interest. Possible applications include ultra-sensitive measurements, and testing fundamental quantum mechanics. By coupling these phonon systems with SQC, one can engineer the phonons at quantum level.
In Fig. 1(a), we describe a hybrid quantum system composed of a micrometer-size carbon nanotube (CNT) longitudinally coupling to a flux qubit. Based on this hybrid system, one can generate high-fidelity nonclassical states of motions of a carbon-nanotube via dissipative quantum engineering [Phys. Rev. B 95, 205415 (2017)]. 
In Fig. 1(b), we propose an inverse optomechanical system, in which the frequency of a mechanical mode is effectively modified by a quantized optical field. Compared with a conventional optomechanical system, the role of mechanical and optical modes are exchanged. Based on this hybrid system, one can realize a strong phonon-photon quadratic coupling and demonstrate phonon dynamical Casimir effects.
Fig. 1  (a) By employing the decoherence channel of a flux qubit, one can engineer the motion of a current-carrying carbon nano-tube into macroscopic superposition states. (b) An inverse optomechanical system (IOMS) we proposed. The SAW cavity length is effectively modulated by the microwave field.

2. Quantum dynamics with longitudinal coupling in SQC

In recent years, much theoretical and experimental research has been devoted to SQCs based on the so-called longitudinal coupling. Compared with the transverse coupling, the longitudinal coupling describes a completely different quantum mechanism and has its inherent advantages. For example, there is no Purcell decay and residual interactions between a qubit and its resonator. 
In Fig. 2(a), we predict that the pure effects of counter-rotating terms in a dipole-dipole-coupling system can be observed, given that the two flux qubits longitudinally couple to a resonator [Phys. Rev. A 96, 063820 (2017)]. 
In Fig. 2(b), we show that the longitudinal freedom of a flux qubit can couple to a bound-tunable measurement resonator. The interaction form is of direct dispersive coupling type. Based on this proposal, one can realize an ideal QND qubit readout without being disturbed by the Purcell effect.
Fig. 2 (a) A proposal to observe pure effects of counter-rotating terms without ultrastrong coupling. (b) A proposal on how to realize an ideal QND readout of a gradiometric flux qubit with a tunable gap. We consider that the qubit couples to a bound-tunable measurement resonator via direct dispersive coulping.

Future projects

1. chiral quanatum optics;
2. giant atoms interacting with artificial quantum environment；

Publications

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  1. X. Wang, Z.-M. Gao, J.-Q. Li, H.-B. Zhu, H.-R. Li, Unconventional Quantum Electrodynamics with Hofstadter-Ladder Waveguide, Phys. Rev. A 106, 043703 (2022)
  2. X. Wang and H.-R. Li, Chiral quantum network with giant atoms, Quantum Sci. Technol. 7, 035007 (2022)
  3. J.-J. Xue, K.-H. Yu, W.-X. Liu, X. Wang and H.-R. Li, Fast generation of cat states in Kerr nonlinear resonators via optimal adiabatic control, New J. Phys. 24, 053015 (2022)
  4. Y.-H. Kang, Y.-H. Chen, X. Wang, J. Song, Y. Xia, A. Miranowicz, S.-B. Zheng, F. Nori, Nonadiabatic geometric quantum computation with cat-state qubits via invariant-based reverse engineering, Phys. Rev. Research 4, 013233 (2022)
  5. W.-X. Liu, Y.-F. Lin, J.-Q. Li and X. Wang, Nonreciprocal Waveguide-QED for Spinning Cavities with Multiple Coupling Points, Front. Phys. 10, 894115 (2022)
  6. Y.-H. Chen, W. Qin, R. Stassi, X. Wang, F. Nori, Fast binomial-code holonomic quantum computation with ultrastrong light-matter coupling, Phys. Rev. Research 3, 033275 (2021)
  7. Y.-L. Chang, J.-Q. Li, W.-Q. Zhu, X.-L. Wu, X. Wang, H.-R. Li, X.-L. Wang, Microwave photonic circulator based on optomechanical-like interactions, Quantum Information Processing 20, 306 (2021)
  8. X. Wang, T. Liu, A. F. Kockum, H.-R. Li, and F. Nori, Tunable Chiral Bound States with Giant Atoms, Phys. Rev. Lett. 126, 043602 (2021)
  9. Y-H. Chen, W. Qin , X. Wang ,A. Miranowicz ,and F. Nori, Shortcuts to Adiabaticity for the Quantum Rabi Model: Efficient Generation of Giant Entangled Cat States via Parametric Amplification, Phys. Rev. Lett. 126, 023602 (2021)
  10. D.-G. Lai, X. Wang, W. Qin, B.-P. Hou, F. Nori, and J.-Q. Liao, Tunable optomechanically induced transparency by controlling the dark-mode effect, Phys. Rev. A 102, 023707 (2020)
  11. W. Qin, Y.-H. Chen, X. Wang, A. Miranowicz, and F. Nori, Strong spin squeezing induced by weak squeezing of light inside a cavity, Nanophotonics, 9, 0513 (2020)
  12. J.-J. Xue, W.-Q. Zhu, Y.-N. He, X. Wang, H.-R. Li, Two-acoustic-cavity interaction mediated by superconducting artificial atoms, Quantum Information Processing, 19, 333 (2020)
  13. C.-M. Han, X. Wang, H. Chen, H.-R. Li, Tunable slow and fast light in an atom-assisted optomechanical system with a mechanical pump, Optics Communications 456, 124605 (2020)
  14. X. Wang, H.-R. Li and Fu-li Li, Generating synthetic magnetism via Floquet engineering auxiliary qubits in phonon-cavity-based lattice, New J. Phys. 20, 033037 (2020)
  15. X. Wang , A. Miranowicz, and F. Nori, Ideal Quantum Nondemolition Readout of a Flux Qubit without Purcell Limitations, Phys. Rev. Appl. 12, 064037 (2019)
  16. X. Wang , W. Qin , A. Miranowicz , S. Savasta, and F. Nori, Unconventional cavity optomechanics: Nonlinear control of phonons in the acoustic quantum vacuum, Phys. Rev. A 100, 063827 (2019)
  17. H. Chen, X. Wang, C.-M. Han and H.-R. Li, Phonon-mediated excitation energy transfer in a detuned multi-sites system, J. Phys. B, 52 075501 (2019).
  18. C.-M. Han, X. Wang, H. Chen and H.-R. Li, Tunable slow and fast light in an atom-assisted optomechanical system with a mechanical pump, Opt. Comm., 456 124605 (2019).
  19. Z.-R. Zhong, X. Wang, W. Qin, Towards quantum entanglement of micromirrors via a two-level atom and radiation pressure, Front. Phys. 13, 5 (2018).
  20. X. Wang, A. Miranowicz, H.-R. Li, Fu-li Li and F. Nori, Two-color electromagnetically induced transparency a mechanical resonator and a qubit, Phys. Rev. A 98, 023821 (2018).  
  21. X.-J. Sun, X. Wang, L.-N. Liu, W.-X. Liu, A.-P. Fang, H.-R. Li, Optical-response properties in hybrid optomechanical systems with quadratic coupling, J. Phys. B, 51, 045504 (2018)
  22. W.-X. Liu, X. Wang, M.-M. Luo, X.-J. Sun, S.-Y. Gao and F.-L. Li, Dipole induced transparency and Aulter–Townes splitting via a dipole emitter coupled to a hybrid photonic-plasmonic resonator, J. Opt. 20, 105401 (2018)
  23. X. Wang, A. Miranowicz, H.-R. Li, and F. Nori, Observing pure effects of counter-rotating terms without ultrastrong coupling: A single photon can simultaneously excite two qubits, Phys. Rev. A 96, 063820 (2017).
  24. W. Qin, X. Wang, A. Miranowicz, Z.-R. Zhong, and F. Nori, Heralded quantum controlled phase gates with dissipative dynamics in macroscopically-distant resonators, Phys. Rev. A, 96, 012315 (2017)
  25. W.-X. Liu, X. Wang, Y.-Q. Chai, S.-Y. Gao, and F.-L. Li, Multiple plasmon resonance in a concentric silver-atomic medium nanoshell, J Appl. Phys. 121, 123102 (2017) 
  26. X. Wang, A. Miranowicz, H.-R. Li, and F. Nori, Hybrid quantum device with a carbon nanotube and a flux qubit for dissipative quantum engineering, Phys. Rev. B 95, 205415 (2017). 
  27. X. Wang, H. Chen, C.-Y Li, and H.-R. Li, Vibration-assisted coherent excitation energy transfer in a detuned dimmer, Chin. Phys. B 26 (3), 037105 (2017).
  28. X. Wang, A. Miranowicz, H.-R. Li, and F. Nori, Multi-output microwave single-photon source using superconducting circuits with longitudinal and transverse couplings, Phys. Rev. A 94, 053858 (2016).
  29. H. Chen, X. Wang, A. P. Fang and H. R. Li, Phonon-assisted excitation energy transfer in photosynthetic systems, Chin. Phys. B, 25 098201 (2016)
  30. X. Wang, A. Miranowicz, H.-R. Li, and F. Nori, Method for observing robust and tunable phonon blockade in a nanomechanical resonator coupled to a charge qubit, Phys. Rev. A 93, 063861 (2016).
  31. X. Wang, H. R. Li, D. X. Chen, W. X. Liu, and F. L. Li, Tunable electromagnetically induced transparency in a composite superconducting system, Opt. Commun. 366, 321 (2016).
  32. X. Wang, H.-R. Li, P.-B Li, C.-W. Jiang, H. Gao, and F.-L. Li, Preparing ground states and squeezed states of nanomechanical cantilevers by fast dissipation, Phys. Rev. A 90, 013838 (2014).

Fundings

 2022-2025 “Theoretical study on chiral quantum networks with superconducting giant atoms”, National Natural Science Foundation of China (NSFC), Grant No. 12174303.

 

 2018-2021 “Quantum Nondemolition measurement of virtual excitations in ultrastrong coupling systems”, National Natural Science Foundation of China (NSFC), Grant No. 11804270.

 

2017-2020 “Detecting the ground-state photons in ultra-strong coupling SQC via parametrical tunable coupling”, China Postdoctoral Science Foundation, Grant No. 2018M631136;

 

2015-2016 The National Scholarship for Ph.D. joint student; China Scholarship Council (CSC);

 

 

Contact

1.    Room B-803, Zhong-ying Buiding, Department of Physics, No.28, Xianning West Road, Xi'an, Shaanxi, 710049, P.R. China.

 

2. Theoretical Quantum Physics Laboratory, Cluster for Pioneering Research, RIKEN. 2-1 Hirosawa, Wako-shi, Saitama 351-0198, Japan

 

 

Email: wangxin.phy at xjtu.edu.cn