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Generic "unnecessary" quantum critical points with minimal degrees of freedom

Cornell Affiliated Author(s)

Author

Chao-Ming Jian
Cenke Xu

Abstract

We explore generic "unnecessary" quantum critical points with minimal degrees of freedom. These quantum critical points can be avoided with strong enough symmetry-allowed deformations of the Hamiltonian, but these deformations are irrelevant perturbations below certain threshold at the quantum critical point. These quantum critical points are hence unnecessary, but also unfine-tuned (generic). The previously known examples of such generic unnecessary quantum critical points involve at least eight Dirac fermions in both two and three spatial dimensions. In this work we seek for examples of generic unnecessary quantum critical points with minimal degrees of freedom. In particular, in three-dimensional space, we identify two examples of such generic unnecessary quantum critical points. The first example occurs in a 3d interacting topological insulator, and it is described by two (3+1)d massless Dirac fermions in the infrared limit; the second example occurs in a 3d topological superconductor, and it is formally described by only one (3+1)d massless Dirac fermion. © 2020 American Physical Society.

Date Published

Journal

Physical Review B

Volume

101

Issue

3

URL

https://www.scopus.com/inward/record.uri?eid=2-s2.0-85078425121&doi=10.1103%2fPhysRevB.101.035118&partnerID=40&md5=b400cc81e16ce63812e47160fed3824f

DOI

10.1103/PhysRevB.101.035118

Group (Lab)

Chao-Ming Jian Group

Funding Source

1920434
DMR-1920434
PHY- 1607611
GBMF4304

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