Magnetic-field-induced metal-insulator quantum phase transition in CaFeAsF near the quantum limit

• 来源期刊: 中国科学:物理学 力学 天文学（英文版）
• 年，卷（期）: 2018,（12）
• 页码范围: 58-62
• 页数: 5页
• 语种: 英文

摘要

The quantum limit,where only the lowest Landau level is occupied by electrons,can be achieved under a high magnetic field when the Landau level splitting is comparable with the Fermi energy.The rather small Fermi pockets and Fermi energy in CaFeAsF reported recently make this compound a good candidate for investigating the electrical transport near the quantum limit.Here,we report high-field experiments up to 65 T on a single-crystalline CaFeAsF,which shows a metal-insulator quantum phase transition tuned by the out-of-plane magnetic field.The obtained critical exponent zv through the finite-size scaling analysis is very close to 4/3.This transition is closely associated with the evolution of electronic states approaching the quantum limit.The resistivity behaviors as a function of field and temperature were evaluated based on Adams-Holstein theory (A-H theory).Moreover,the in-plane component of the field,which does not affect the transport behavior in the classical region,suppressed the magnetoresistance near the quantum limit.