Mott Insulator to high \tc Superconductor via Pressure: Resonating Valence Bond theory and prediction of new Systems

TL;DR

This paper explores a pressure-induced transition from Mott insulators to high-temperature superconductors in spin-
6 systems using RVB theory, proposing a new model and predicting candidate materials.

Contribution

It introduces a generalized t-J model with conserved doubly occupied and empty sites, offering a novel perspective on pressure-induced high  superconductivity.

Findings

Proposes a 'strong coupling' hypothesis linking Mott transition to self doping.

Predicts new candidate systems for pressure-induced high  superconductivity.

Establishes an equivalence to the regular t-J model for these systems.

Abstract

Mott insulator superconductor transition, via pressure and no external doping, is studied in orbitally non degenerate spin-\half systems. It is presented as another RVB route to high \tc superconductivity. We propose a `strong coupling' hypothesis which helps to view first order Mott transition as a self doping process that also preserves superexchange on metal side . We present a generalized t-J model where a conserved $N_0$ doubly occupied ($e^-$) sites and $N_0$ empty sites ($e^+$) hop in the background of $N - 2 N_0$ singly singly occupied (neutral) sites in a lattice of N sites. An equivalence to the regular t-J model is made and some old and new systems are predicted to be candidates for pressure induced high \tc superconductivity.