Title: Associate Professor, Doctoral Supervisor
Contact number:
Department: Computational Physics
E-mail: rfei@bit.edu.cn
Address: A406-4, Liangxiang South Campus, Beijing Institute of Technology

His research interests are the theoretical calculation of electron-light interaction and its application in the new generation of low-power optoelectronics and spintronics devices. At the same time, the relevant first principles calculation methods and programs are developed. His current research interests include the following: (1) the mechanism of the interaction between charge, spin and light; (2) Development of high order computational tools for the interaction of matter and light; (3) The influence of quantum multibodies on light and nonlinear optical effects in quantum materials.

2012-08 to 2017-07, Washington University, St. Louis, USA, Ph. D. in Physics 2009-09 to 2012-07, Peking University, M.S. in Condensed Matter Physics 2005-09 to 2009-07, Anhui University, B.S.

2022-06 to present, "Special Young Scholar", School of Physics, Beijing Institute of Technology, Associate Professor 2019-08-2022-04, Postdoctoral Fellow, Washington University, St. Louis, USA, 2017-08-2019, University of Pennsylvania, USA, Postdoctoral Fellow

We have long used density functional theory, quantum field theory, Monte Carlo simulation and other theories and computational methods, including first principles, to explore the novel physical properties of quantum materials and their regulatory means. The following results are obtained: (1) It is first proposed that the low-dimensional structure of the IV-VI group semiconductor is a ferroelectric that is broken by space inversion, and revealed that the two-dimensional ferroelectric phase transition mainly depends on the spontaneous polarization and the interaction of electric dipoles, and achieved a Curie transition temperature higher than room temperature; And it was verified by the follow-up experiment. (2) The mechanism of interaction between strong light and low-symmetry materials is systematically studied, and a new photocurrent mechanism is proposed to generate high spin polarization photocurrent in space inversion broken materials and a new photocurrent mechanism in topological magnetic materials broken by time inversion; At the same time, a first principles program based on Green function method is developed. (3) It is suggested that pressure can effectively regulate the physical properties of the materials with three or more rotational symmetry breaking.
Before joining Beijing Institute of Technology, he published 31 SCI articles such as Phys. Rev. Lett., Nano Lett. Nat. Electronics, Nat. Nano., Nat. Comm., etc. SCI he cited Google Scholar for more than 4000 times, H index 22. It cited papers including Review of Modern Physics, Science, Nature, Nat. Photonics, Nat. Nanotechnol., PRL, etc. One article includes Phys. Rev. Lett. (2 articles), Nano Lett. (3 articles), Nat.Electronics, PRB/APL several articles. NLOpack, an efficient parallel computing package, was developed to calculate the nonlinear interactions of electron, spin and light of matter.
Representative papers (corresponding authors *, together #)
1. Ruixiang Fei*, W. Song, L. Pusey-Nazzaro, L. Yang*, PT-symmetry enabled spin circular photogalvanic effect in antiferromagnetic insulators, Physical Review Letters, 127, 207402 (2021).
2. Ruixiang Fei*, S. Yu, Y. Lu, L. Zhu, L. Yang*, Switchable enhanced spin photocurrent in Rashba and cubic Dresselhaus ferroelectric semiconductors, Nano Letters, 21, 2265-2271(2021)
3. Ruixiang Fei, L. Yang*, Room-temperature ferroelectric switching, Nature Electronics, 4, 703 (2021) (News & Views)
4. Ruixiang Fei, W. Kang*, and L. Yang*, Ferroelectricity and phase transitions in monolayer group-IV monochalcogenides, Physical Review Letters 117, 097601 (2016). (Citation: 360. First work predicting unexpected temperature-robust ferroelectricity in 2D structures)
5. Ruixiang Fei, A. Faghaninia, R. Soklaski, J.-A. Yan, C. Lo, and L. Yang*, Enhanced Thermoelectric Efficiency via Orthogonal Electrical and Thermal Conductances in Phosphorene, Nano letters 14, 6393 (2014). (Citation: 624. Highlighted by review in PNAS of black phosphorus)
6. Ruixiang Fei and L. Yang*, Strain-Engineering the Anisotropic Electrical Conductance of Few-Layer Black Phosphorus. Nano Letters 14, 2884 (2014). (Citation: 1100)
7. Ruixiang Fei, L. Z. Tan, A. M. Rappe*. Shift-current bulk photovoltaic effect influenced by quasiparticle and exciton. Physical Review B 101, 045104 (2020)
8. Ruixiang Fei, W. Song, L. Yang*. Giant linearly-polarized photogalvanic effect and second harmonic generation in two-dimensional axion insulators. Physical Review B 102, 035440 (2020)
9. Ruixiang Fei, W. Li, J. Li, and L. Yang*, Giant Piezoelectricity in Monolayer Group IV Monochalcogenides: SnSe, SnS, GeSe, and GeS. Applied Physics Letters 107, 173104 (2015). (Citation: 540. Selected by Nat. Phys. Rev. as one of ten most important works on black phosphorus and its isoelectronic materials)
10. Ruixiang Fei, V. Tran, and L. Yang*, Topologically protected Dirac cones in compressed bulk black phosphorus, Physical Review B 91, 195319 (2015). (Citation: 100)