Department of Physics Papers

Document Type

Journal Article

Date of this Version

5-15-2001

Publication Source

Europhysics Letters

Volume

54

Issue

4

Start Page

508

Last Page

514

DOI

10.1209/epl/i2001-00276-4

Abstract

Using an electron spin resonance spectrometer covering a wide range of frequency and magnetic field, we have measured the low-energy excitations of the S = ½ tetragonal antiferromagnets, Sr2CuO2Cl2 and Sr2Cu3O4Cl2. Our observations of in-plane energy gaps of order 0.1 meV at zero external magnetic field are consistent with a spin-wave calculation, which includes several kinds of quantum fluctuations that remove frustration. Such gaps vanish for classical spins, and were too small to be observed by other techniques. Results agree with other experiments and with exchange anisotropy parameters determined from a five-band Hubbard model.

Copyright/Permission Statement

This is an author-created, un-copyedited version of an article accepted for publication in Europhysics Letters. IOP Publishing Ltd is not responsible for any errors or omissions in this version of the manuscript or any version derived from it. The definitive publisher authenticated version is available online at dx.doi.org/10.1209/epl/i2001-00276-4.

Comments

At the time of publication, author A. Brooks Harris was affiliated with the Massachusetts Institute of Technology, Cambridge, Massachusetts. Currently, he is a faculty member in the Physics Department at the University of Pennsylvania.

Included in

Physics Commons

Share

COinS
 

Date Posted: 20 August 2015

This document has been peer reviewed.