Fractional quantum Hall effect with unconventional pairing in monolayer graphene

ORAL

Abstract

There is experimental evidence for fractional quantum Hall effect at half-filling in the n=3 Landau level of monolayer graphene [1]. To understand its origin, we construct BCS wave functions of composite fermions [2] for different pairing channels and minimize the Coulomb interaction energy by varying two variational parameters of the wave function. We search for pairing instability as a function of the variational parameters and find that the composite fermion Fermi sea is unstable to an f-wave pairing [3].

[1] Y. Kim, A. C. Balram, T. Taniguchi, K. Watanabe, J. K. Jain, and J. H. Smet, Even denominator fractional quantum Hall states in higher Landau levels of graphene, Nature Physics 15, 154 (2019).

[2] Anirban Sharma, Songyang Pu, Ajit C. Balram, Jainendra K. Jain, Bardeen-Cooper-Schrieffer pairing of composite fermions, Physical Review B 104, 205303 (2021).

[3] Anirban Sharma, Songyang Pu, Ajit C. Balram, Jainendra K. Jain, Fractional quantum Hall effect with unconventional pairing in monolayer graphene, submitted (2022).

*A.S. and J.K.J. were supported by the US National Science Foundation grant no. DMR-2037990. S.P. was supported (at Penn State) by the U.S. Department of Energy, Office of Basic Energy Sciences, under Grant no. DE-SC-0005042 and is supported (at Leeds) by the Leverhulme Trust Research Leadership Award RL-2019-015 and EPSRC grant EP/R020612/1. A. C. B. acknowledges the Science and Engineering Research Board (SERB) of the Department of Science and Technology (DST) for financial support through the Start-up Grant SRG/2020/000154.

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Presenters

  • Anirban Sharma

    • Pennsylvania State University

Authors

  • Anirban Sharma

    • Pennsylvania State University

  • Songyang Pu

    • Univ of Leeds
    • University of Leeds

  • Ajit C Coimbatore Balram

    • Institute of Mathematical Sciences, India
    • Institute of Mathematical Sciences, CIT Campus
    • The Institute of Mathematical Sciences (IMSc)

  • Jainendra K Jain

    • Pennsylvania State University