SKM 2023 – wissenschaftliches Programm
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TT: Fachverband Tiefe Temperaturen
TT 47: Quantum-Critical Phenomena
TT 47.6: Vortrag
Donnerstag, 30. März 2023, 10:45–11:00, HSZ 204
Transverse-field quantum phase transitions in CoNb2O6 — •Alexander Engelhardt1, Andreas Wendl1, Andreas Bauer1, Andreas Erb2, Matthias Vojta3, and Christian Pfleiderer1 — 1Physik-Department, Technical University of Munich, D-85748 Garching, Germany — 2Walther-Meißner-Institut, D-85748 Garching, Germany — 3Institut for Theoretical Physics, Technical University of Dresden, D-85748 Garching, Germany
The ferromagnetic Ising chain in a transverse magnetic field displays the perhaps best understood theoretical example of a quantum phase transition. One of the closest realizations has been reported in the columbite compound CoNb2O6 [1,2,3], in which, however, weak interchain couplings result in incommensurate antiferromagnetism as a function of decreasing temperature, followed by a transition to commensurate antiferromagnetic order. We have grown high-quality single-crystal CoNb2O6 by means of optical float-zoning. Measuring the transverse magnetic ac susceptibility of a spherical sample down to 90 mK under arbitrary field orientations, we have mapped out the emergence of the quantum phase transitions associated with the incommensurate and commensurate antiferromagnetic order under transverse field, as well as the evolution of the magnetic phase diagram when systematically tilting the magnetic field away from the hard magnetic axis.
[1] R. Coldea et al., Science 327, 177 (2010)
[2] M. Fava et al., PNAS 117, 25219 (2020)
[3] C. M. Morris et al., Nat. Phys. 17, 852 (2021)