Direct evidence of nuclear spin waves in Nd$_2$CuO$_4$ by high-resolution neutron-spin-echo spectroscopy

TL;DR

This study provides direct experimental evidence of nuclear spin wave dispersion in Nd$_2$CuO$_4$ at very low temperatures using neutron spin-echo spectroscopy, revealing the interaction range of nuclear spins.

Contribution

First direct observation of nuclear spin wave dispersion in Nd$_2$CuO$_4$ using high-resolution neutron spin-echo spectroscopy at millikelvin temperatures.

Findings

Confirmed dispersion of nuclear spin waves in Nd$_2$CuO$_4$ at 30 mK

Estimated the Suhl-Nakamura interaction range to be about 10 Å

Demonstrated the effectiveness of neutron spin-echo spectroscopy for nuclear spin dynamics

Abstract

We investigated the dispersion of nuclear spin waves in Nd$_2$CuO$_4$ by using neutron spin-echo spectroscopy at millikelvin temperatures. Our results show unambiguously the existence of dispersion of nuclear spin waves in Nd$_2$CuO$_4$ at T = 30 mK. A fit of the dispersion data with the spin wave dispersion formula gave the Suhl-Nakamura interaction range to be of the order of 10 {\AA}.