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arXiv · 0803.3720

Quantum Magnets under Pressure: Controlling Elementary Excitations in TlCuCl3

Ch. Rüegg·B. Normand·M. Matsumoto·A. Furrer·D. McMorrow·K. Krämer·H. -U. Güdel·S. Gvasaliya·H. Mutka·M. Boehm
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Abstract

We follow the evolution of the elementary excitations of the quantum antiferromagnet TlCuCl3 through the pressure-induced quantum critical point, which separates a dimer-based quantum disordered phase from a phase of long-ranged magnetic order. We demonstrate by neutron spectroscopy the continuous emergence in the weakly ordered state of a low-lying but massive excitation corresponding to longitudinal fluctuations of the magnetic moment. This mode is not present in a classical description of ordered magnets, but is a direct consequence of the quantum critical point.

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Ch. Rüegg, B. Normand, M. Matsumoto, A. Furrer, D. McMorrow, K. Krämer, H. -U. Güdel, S. Gvasaliya, H. Mutka, M. Boehm. 2008-03-26. Quantum Magnets under Pressure: Controlling Elementary Excitations in TlCuCl3. https://doi.org/10.1103/physrevlett.100.205701

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