Quantum limit in a quasi-one-dimensional conductor in a high tilted magnetic field

TL;DR

This paper provides a quantum mechanical analysis of electron spectra in quasi-one-dimensional conductors under high tilted magnetic fields, confirming the existence of Fermi-liquid to non-Fermi-liquid crossovers depending on magnetic field orientation.

Contribution

It advances previous semi-classical studies by solving the quantum problem, demonstrating the transition from 2D to 1D electron spectra in high magnetic fields, and predicts feasible conditions for observing these effects.

Findings

High magnetic fields induce a 2D electron spectrum when aligned with crystallographic axes.

Far from the axes, the spectrum becomes 1D, promoting non-Fermi-liquid behavior.

Transitions between Fermi-liquid and non-Fermi-liquid states are feasible at 20-25 T.

Abstract

Recently, we have suggested Fermi-liquid - non-Fermi-liquid angular crossovers which may exist in quasi-one-dimensional (Q1D)conductors in high tilted magnetic fields [see A.G. Lebed, Phys. Rev. Lett. $\textbf{115}$, 157001 (2015).] All calculations in the Letter, were done by using the quasi-classical Peierls substitution method, whose applicability in high magnetic fields was questionable. Here, we solve a fully quantum mechanical problem and show that the main qualitative conclusions of the above mentioned Letter are correct. In particular, we show that in high magnetic fields, applied along one of the two main crystallographic axis, we have 2D electron spectrum, whereas, for directions of high magnetic fields far from the axes, we have 1D electron spectrum. The later is known to promote non-Fermi-liquid properties. As a result, we expect the existence of Fermi-liquid - non-Fermi-liquid angular crossovers or phase transitions. Electronic parameters of Q1D conductor (Per)$_2$Pt(mnt)$_2$ show that such transitions can appear in feasible high magnetic fields of the order of $H \simeq 20-25 \ T$.