Orbit topology analysed from $\pi$ phase shift of magnetic quantum oscillations in three-dimensional Dirac semimetal

التفاصيل البيبلوغرافية
العنوان: Orbit topology analysed from $\pi$ phase shift of magnetic quantum oscillations in three-dimensional Dirac semimetal
المؤلفون: Lee, Sang-Eon, Oh, Myeong-jun, Ji, Sanghyun, Kim, Jinsu, Jun, Jin Hyun, Kang, Woun, Jo, Younjung, Jung, Myung-Hwa
سنة النشر: 2020
المجموعة: Condensed Matter
مصطلحات موضوعية: Condensed Matter - Mesoscale and Nanoscale Physics
الوصف: 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 Lifshiftz-Kosevich 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, NbSb$_2$. With varying the direction of the magnetic field, an abrupt $\pi$ phase shift is observed due to the interference between the spin-degenerate orbits. We investigate the effect of cyclotron mass on the $\pi$ phase shift and verify its close relation to the phase from the Zeeman coupling. We find that the $\pi$ phase shift occurs when the cyclotron mass is 1/2 of the electron mass, indicating the effective spin gyromagnetic ratio is $g_s$ = 2. Our approach is not only useful for analysing 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 $g_s$ value of the material.
Comment: 17 pages, 4 figures
نوع الوثيقة: Working Paper
DOI: 10.1073/pnas.2023027118
URL الوصول: http://arxiv.org/abs/2010.10826
رقم الأكسشن: edsarx.2010.10826
قاعدة البيانات: arXiv