TY - JOUR

T1 - Orbit topology analyzed from π phase shift of magnetic quantum oscillations in three-dimensional Dirac semimetal

AU - Lee, Sang Eon

AU - Oh, Myeong Jun

AU - Ji, Sanghyun

AU - Kim, Jinsu

AU - Jun, Jin Hyeon

AU - Kang, Woun

AU - Jo, Younjung

AU - Jung, Myung Hwa

N1 - Funding Information:
ACKNOWLEDGMENTS. This work was supported by the National Research Foundation of Korea Grants 2020R1A2C3008044, 2019R1A2C1089017, and 2018R1D1A1B07050087.
Publisher Copyright:
© 2021 National Academy of Sciences. All rights reserved.

PY - 2021/7/20

Y1 - 2021/7/20

N2 - With the emergence of Dirac fermion physics in the field of condensed matter, magnetic quantum oscillations (MQOs) have been used to discern the topology of orbits in Dirac materials. However, many previous researchers have relied on the single-orbit Lifshitz–Kosevich (LK) formula, which overlooks the significant effect of degenerate orbits on MQOs. Since the single-orbit LK formula is valid for massless Dirac semimetals with small cyclotron masses, it is imperative to generalize the method applicable to a wide range of Dirac semimetals, whether massless or massive. This report demonstrates how spin-degenerate orbits affect the phases in MQOs of three-dimensional massive Dirac semimetal, NbSb2. With varying the direction of the magnetic field, an abrupt π phase shift is observed due to the interference between the spin-degenerate orbits. We investigate the effect of cyclotron mass on the π phase shift and verify its close relation to the phase from the Zeeman coupling. We find that the π phase shift occurs when the cyclotron mass is half of the electron mass, indicating the effective spin gyromagnetic ratio as gs = 2. Our approach is not only useful for analyzing MQOs of massless Dirac semimetals with a small cyclotron mass but also can be used for MQOs in massive Dirac materials with degenerate orbits, especially in topological materials with a sufficiently large cyclotron mass. Furthermore, this method provides a useful way to estimate the precise gs value of the material.

AB - With the emergence of Dirac fermion physics in the field of condensed matter, magnetic quantum oscillations (MQOs) have been used to discern the topology of orbits in Dirac materials. However, many previous researchers have relied on the single-orbit Lifshitz–Kosevich (LK) formula, which overlooks the significant effect of degenerate orbits on MQOs. Since the single-orbit LK formula is valid for massless Dirac semimetals with small cyclotron masses, it is imperative to generalize the method applicable to a wide range of Dirac semimetals, whether massless or massive. This report demonstrates how spin-degenerate orbits affect the phases in MQOs of three-dimensional massive Dirac semimetal, NbSb2. With varying the direction of the magnetic field, an abrupt π phase shift is observed due to the interference between the spin-degenerate orbits. We investigate the effect of cyclotron mass on the π phase shift and verify its close relation to the phase from the Zeeman coupling. We find that the π phase shift occurs when the cyclotron mass is half of the electron mass, indicating the effective spin gyromagnetic ratio as gs = 2. Our approach is not only useful for analyzing MQOs of massless Dirac semimetals with a small cyclotron mass but also can be used for MQOs in massive Dirac materials with degenerate orbits, especially in topological materials with a sufficiently large cyclotron mass. Furthermore, this method provides a useful way to estimate the precise gs value of the material.

KW - Topological semimetal | magnetic quantum oscillation | orbit topology | spin-degenerate system

UR - http://www.scopus.com/inward/record.url?scp=85110373314&partnerID=8YFLogxK

U2 - 10.1073/pnas.2023027118

DO - 10.1073/pnas.2023027118

M3 - Article

C2 - 34266947

AN - SCOPUS:85110373314

SN - 0027-8424

VL - 118

JO - Proceedings of the National Academy of Sciences of the United States of America

JF - Proceedings of the National Academy of Sciences of the United States of America

IS - 29

M1 - e2023027118

ER -