Onsager phase factor of quantum oscillations in the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2)

TL;DR

This study investigates the Onsager phase factor in quantum oscillations of the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2), revealing the importance of field-dependent phase contributions for accurate modeling at high magnetic fields.

Contribution

It demonstrates the necessity of including field-dependent phase factors, beyond the Maslov index, to accurately interpret quantum oscillation data in this organic metal.

Findings

Field-dependent phase factors are essential for high-field data analysis.

Evidence supports the existence of additional phase contributions in quantum oscillations.

The study enhances understanding of Fermi surface behavior in multiband organic metals.

Abstract

De Haas-van Alphen oscillations are studied for Fermi surfaces illustrating the Pippard's model, commonly observed in multiband organic metals. Field- and temperature-dependent amplitude of the various Fourier components, linked to frequency combinations arising from magnetic breakdown between different bands, are considered. Emphasis is put on the Onsager phase factor of these components. It is demonstrated that, in addition to the usual Maslov index, field-dependent phase factors must be considered to precisely account for the data at high magnetic field. We present compelling evidence of the existence of such contributions for the organic metal theta-(BEDT-TTF)4CoBr4(C6H4Cl2).