Unexpected magnetic phase in the weakly ordered spin-1/2 chain cuprate Sr2CuO3

Loading...
Thumbnail Image

Access rights

openAccess
publishedVersion

URL

Journal Title

Journal ISSN

Volume Title

A1 Alkuperäisartikkeli tieteellisessä aikakauslehdessä

Date

2020-05-15

Major/Subject

Mcode

Degree programme

Language

en

Pages

5

Series

Physical Review B, Volume 101, issue 20

Abstract

The magnetic phase diagram of a spin-12 chain antiferromagnet Sr2CuO3 is studied by an ultrasound phase-sensitive detection technique. The system is in the extreme proximity of the Luttinger-liquid quantum-critical point and we observe an unusually strong effect of magnetic field, which is very weak compared to the in-chain interaction, on the Néel ordering temperature. Inside the ordered phase, we detect an unexpected, field-induced continuous phase transition. The transition is accompanied by softening of magnetic excitation observed by electron-spin resonance, which in previous work [E. G. Sergeicheva et al., Phys. Rev. B 95, 020411(R) (2017)2469-995010.1103/PhysRevB.95.020411] was associated with a longitudinal (amplitude) mode of the order parameter. These results suggest a transition from a transverse collinear antiferromagnet to an amplitude-modulated spin-density-wave phase in a very weak magnetic field, which is unexpected for a system of weakly coupled Heisenberg spin-12 chains.

Description

Keywords

QUANTUM CRITICALITY, NEEL TEMPERATURE, FIELD, ANTIFERROMAGNETS, SUSCEPTIBILITY, DYNAMICS, S=1/2

Other note

Citation

Sergeicheva, E G, Sosin, S S, Gorbunov, D, Zherlitsyn, S, Gu, G D & Zaliznyak, I A 2020, ' Unexpected magnetic phase in the weakly ordered spin-1/2 chain cuprate Sr2CuO3 ', Physical Review B, vol. 101, no. 20, 201107 . https://doi.org/10.1103/PhysRevB.101.201107