Shubnikov-de Haas and de Haas-van Alphen oscillation in Czochralski grown CoSi single crystal

TL;DR

This study investigates quantum oscillations in high-quality Czochralski-grown CoSi single crystals, revealing detailed electronic properties, effective masses, and Fermi surface features through SdH and dHvA measurements.

Contribution

It provides the first detailed analysis of quantum oscillations in Czochralski-grown CoSi, including effective masses, Fermi surface frequencies, and scattering lifetimes.

Findings

Magnetoresistance reaches 610% at 2 K for specific orientations.

Three dHvA frequencies identified, including a tiny hole pocket at the Gamma point.

Transport lifetime is comparable to quantum lifetime in 3D CoSi.

Abstract

Anisotropic transport, Shubnikov-de Haas (SdH), and de Haas-van Alphen (dHvA) quantum oscillations studies are reported on a high-quality CoSi single crystal grown by the Czochralski method. Temperature-dependent resistivities indicate the dominating electron-electron scattering. Magnetoresistance (MR) at 2 K reaches 610% for I||[111] and B||[01-1], whereas it is 500% for I||[01-1] and B||[111]. A negative slope in field-dependent Hall resistivity suggests electrons are the majority carriers. The carrier concentration extracted from Hall conductivity indicates no electron-hole compensation. In 3D CoSi, the electron transport lifetime is found to be approximately in the same order as quantum lifetime, whereas in 2D electron gas the long-range scattering drives the transport life much larger than the quantum lifetime. From linear and Hall SdH oscillations the effective masses and Dingle temperatures have been calculated. The dHvA oscillation reveals three frequencies at 18 ($\gamma$), 558 ($\alpha$) and 663 T ($\beta$)), whereas, SdH oscillation results in only two frequencies $\alpha$ and $\beta$. The $\gamma$ frequency observed in dHvA oscillation is a tiny hole pocket at the $\Gamma$ point.