Positive longitudinal magnetoconductivity induced by chiral magnetic effect in mercury selenide

Abstract

A negative longitudinal magnetoresistance without any sign of saturation was found in a non-centrosymmetric Weyl semimetal (WSM) candidate mercury selenide in an electron concentration range of 5.5 × 1015–1.7 × 1017 cm−3 and a temperature range of 0.33–150 K. The magnitude of the effect varies with a sample from 10% up to 30% in a magnetic field of 12 T at T = 150 K. Moreover, the positive contribution to magnetoconductivity has a characteristic quadratic dependence on the magnetic field, increasing with a charged center concentration at T = 150 K. The most likely explanation for the discovered longitudinal magnetoconductivity feature lies in the chiral magnetic effect, which is inherent to WSMs. The role of the Dyakonov–Perel mechanism in inter-nodal spin relaxation is discussed in regard to HgSe.