Spin-roton excitations in the cuprate superconductors

TL;DR

This paper introduces spin-rotons as new elementary excitations in doped Mott insulators, linking their energy to the superconducting transition temperature and connecting them with experimental observations in high-Tc cuprates.

Contribution

It proposes the concept of spin-rotons and derives a simple formula for Tc based on their energy scale, providing a new understanding of high-Tc superconductivity.

Findings

Spin-rotons are identified as key excitations in doped Mott insulators.

The Tc formula relates transition temperature to spin-roton energy, Tc=Eg/6.

Experimental signatures of spin-rotons match neutron and Raman scattering data.

Abstract

We identify a new kind of elementary excitations, spin-rotons, in the doped Mott insulator. They play a central role in deciding the superconducting transition temperature Tc, resulting in a simple Tc formula,Tc=Eg/6, with Eg as the characteristic energy scale of the spin rotons. We show that the degenerate S=1 and S=0 rotons can be probed by neutron scattering and Raman scattering measurements, respectively, in good agreement with the magnetic resonancelike mode and the Raman A1g mode observed in the high-Tc cuprates.