Shubnikov-de Haas oscillations spectrum of the strongly correlated quasi-2D organic metal (ET)8[Hg4Cl12(C6H5Br)]2 under pressure

TL;DR

This study investigates how pressure affects the Shubnikov-de Haas oscillations in a quasi-2D organic metal, revealing changes in Fermi surface properties, effective masses, and scattering rates, with implications for electron correlations.

Contribution

It provides the first detailed analysis of pressure effects on SdH spectra in this specific strongly correlated organic metal, highlighting the evolution of its Fermi surface and electron interactions.

Findings

Large Fourier components in SdH spectra persist under pressure.

Magnetic breakdown field and effective masses decrease with pressure.

Scattering rate increases as pressure is applied.

Abstract

Pressure dependence of the Shubnikov-de Haas (SdH) oscillations spectra of the quasi-two di- mensional organic metal (ET)8[Hg4Cl12(C6H5Br)]2 have been studied up to 1.1 GPa in pulsed magnetic fields of up to 54 T. According to band structure calculations, its Fermi surface can be regarded as a network of compensated orbits. The SdH spectra exhibit many Fourier components typical of such a network, most of them being forbidden in the framework of the semiclassical model. Their amplitude remains large in all the pressure range studied which likely rules out chemical potential oscillation as a dominant contribution to their origin, in agreement with recent calculations relevant to compensated Fermi liquids. In addition to a strong decrease of the magnetic breakdown field and effective masses, the latter being likely due to a reduction of the strength of electron correlations, a sizeable increase of the scattering rate is observed as the applied pressure increases. This latter point, which is at variance with data of most charge transfer salts is discussed in connection with pressure-induced features of the temperature dependence of the zero-field interlayer resistance