Evidence for weak-antilocalization–weak-localization crossover and metal-insulator transition in CaCu₃Ru₄O₁₂ thin films

¹ Institute of Physics - Sachivalaya Marg, Bhubaneswar, 751005, India
² Homi Bhabha National Institute - Anushakti Nagar, Mumbai, 400085, India
³ Department of Physics, Indian Institute of Science - Bangalore, 560012, India
⁴ Condensed Matter Theory and Computational Lab, Department of Physics, Indian Institute of Technology Madras, India

^(a) subhadip.j@iopb.res.in
^(b) dsamal@iopb.res.in

Received: 29 August 2020
Accepted: 7 December 2020

Abstract

Artificial confinement of electrons by tailoring the layer thickness has turned out to be a powerful tool to harness control over competing phases in nano-layers of complex oxides. We investigate the effect of dimensionality on transport properties of d-electron–based heavy-fermion metal CaCu₃Ru₄O₁₂. Transport behavior evolves from metallic to localized regime upon reducing thickness and a metal-insulator transition is observed below 3 nm film thickness for which sheet resistance crosses , the quantum resistance in 2D. Magnetotransport study reveals a strong interplay between inelastic and spin-orbit scattering lengths upon reducing thickness, which results in weak-antilocalization (WAL) to weak-localization (WL) crossover in magnetoconductance.