Document Type

Article

Publication Date

2009

Publication Title

Physical Review Letters

Abstract

We report magnetocaloric and magnetic-torque evidence that in Cs2CuBr4—a geometrically frustrated Heisenberg S 1⁄4 12 triangular-lattice antiferromagnet—quantum fluctuations stabilize a series of spin states at simple increasing fractions of the saturation magnetization Ms. Only the first of these states—at M 1⁄4 13 Ms—has been theoretically predicted. We discuss how the higher fraction quantum states might arise and propose model spin arrangements. We argue that the first-order nature of the transitions into those states is due to strong lowering of the energies by quantum fluctuations, with implications for the general character of quantum phase transitions in geometrically frustrated systems.

Volume

102

Issue

257201

DOI

10.1103/PhysRevLett.102.257201

Rights

c. 2009 The American Physical Society

Included in

Physics Commons

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