Excitations from a chiral magnetized state of a frustrated quantum spin liquid

Journal Article · Thu Jan 01 00:00:00 EST 2009 · Physical Review B

OSTI ID:969662

Garlea, Vasile O ^[1]; Zheludev, Andrey I ^[1]; Tsvelik, A. ^[2]; Regnault, L. -P. ^[3]; Habicht, Klaus ^[4]; Kiefer, K. ^[4]; Roessli, Bertrand ^[5]

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1. ORNL
2. Brookhaven National Laboratory (BNL)
3. CEA, Grenoble, France
4. Hahn-Meitner Institut, Berlin, Germany
5. Swiss Spallation Neutron Source SINQ

We study excitations in weakly interacting pairs of quantum spin ladders coupled through geometrically frustrated bonds. The ground state is a disordered spin liquid, at high fields replaced by an ordered chiral helimagnetic phase. The spectra observed by high-field inelastic neutron scattering experiments on the prototype compound Sul Cu2Cl4 are qualitatively different from those in the previously studied frustration-free spin liquids. Beyond the critical field Hc = 3.7 T, the soft mode that drives the quantum phase transition spawns two separate excitations: a gapless Goldstone mode and a massive magnon. Additional massive quasiparticles are clearly visible below Hc, but are destroyed in the ordered phase. In their place one observes a sharply bound excitation continuum.

• Research Organization: Oak Ridge National Lab. (ORNL), Oak Ridge, TN (United States). High Flux Isotope Reactor (HFIR)
• Sponsoring Organization: USDOE Office of Science (SC)
• DOE Contract Number: DE-AC05-00OR22725
• OSTI ID: 969662
• Journal Information: Physical Review B, Vol. 80, Issue 21; ISSN 1098-0121
• Country of Publication: United States
• Language: English

Related Subjects

72 PHYSICS OF ELEMENTARY PARTICLES AND FIELDS
CRITICAL FIELD
EXCITATION
GROUND STATES
NEUTRONS
SCATTERING
SPECTRA
SPIN