Publication Date:
2017-01-28
Description:
Author(s): E. Constable, R. Ballou, J. Robert, C. Decorse, J.-B. Brubach, P. Roy, E. Lhotel, L. Del-Rey, V. Simonet, S. Petit, and S. deBrion In the field of geometrically frustrated magnetism, the very nature of the ground state of Tb 2 Ti 2 O 7 has remained a long-standing conundrum. In this pyrochlore material, no conventional spin-ice or long-range magnetic order is stabilized, even at very low temperatures. Quantum fluctuations are suspected of being at the origin of such an exotic quantum phase, yet so far there is no conclusive evidence. Here, high-resolution synchrotron-based terahertz spectroscopy probes the lowest energy excitations of Tb 2 Ti 2 O 7 . By exciting transitions within the crystal electric field and crystal lattice, it is revealed that a double hybridization of crystal-field phonon modes is present across a broad temperature range. This unique vibronic process triggers coupling between several degrees of freedom that provides a crucial path for quantum spin-flip fluctuations to inhibit the stabilization of conventional magnetic states. While providing evidence for the unique quantum phase in Tb 2 Ti 2 O 7 , the result also highlights the powerful and complementary nature of terahertz spectroscopy as a probe in the study of exotic magnetic and frustrated phases. [Phys. Rev. B 95, 020415(R)] Published Fri Jan 27, 2017
Keywords:
Magnetism
Print ISSN:
1098-0121
Electronic ISSN:
1095-3795
Topics:
Physics
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