Angle-dependent magnetoresistance oscillations due to magnetic breakdown orbits

TL;DR

This paper reports experimental evidence of angle-dependent magnetoresistance oscillations caused by magnetic breakdown in an organic superconductor, validating Pippard's semiclassical model through high-pressure and high-field measurements.

Contribution

It provides the first experimental confirmation of magnetic breakdown-induced oscillations in this material, expanding understanding of magnetoresistance phenomena.

Findings

Oscillations observed under high pressure and magnetic fields.

Similar oscillations found at ambient pressure after suppressing other effects.

Results support Pippard's semiclassical magnetic breakdown theory.

Abstract

We present experimental evidence for a hitherto unconfirmed type of angle-dependent magnetoresistance oscillation caused by magnetic breakdown. The effect was observed in the organic superconductor kappa-(BEDT-TTF)$_2$Cu(NCS)$_2$ using hydrostatic pressures of up to 9.8 kbar and magnetic fields of up to 33 T. In addition, we show that similar oscillations are revealed in ambient pressure measurements, provided that the Shubnikov-de Haas oscillations are suppressed either by elevated temperatures or filtering of the data. These results provide a compelling validation of Pippard's semiclassical picture of magnetic breakdown.