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arXiv · 1103.1537

Collective Phenomena in the LiHo_xY_{1-x}F4 Quantum Ising Magnet: Recent Progress and Open Questions

Michel J. P. Gingras·Patrik Henelius
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Abstract

In LiHo_xY_{1-x}F4, the magnetic Holmium Ho^{3+} ions behave as effective Ising spins that can point parallel or antiparallel to the crystalline c-axis. The predominant inter-Holmium interaction is dipolar, while the Y^{3+} ions are non-magnetic. The application of a magnetic field Bx transverse to the c-axis Ising direction leads to quantum spin-flip fluctuations, making this material a rare physical realization of the celebrated transverse field Ising model. The problems of classical and transverse-field-induced quantum phase transitions in LiHo_xY_{1-x}F_4 in the dipolar ferromagnetic (x=1), diluted ferromagnetic (0.25 <~ x < 1) and highly diluted x<~0.25 dipolar spin glass regimes have attracted much experimental and theoretical interest over the past twenty-five years. Two questions have received particular attention: (i) is there an {\it antiglass} (quantum disordered) phase at low Ho^{3+} concentration and (ii) what is the mechanism responsible for the fast Bx-induced destruction of the ferromagnetic (0.25 <~ x < 1) and spin glass (x <~ 0.25) phases? This paper reviews some of the recent theoretical and experimental progress in our understanding of the collective phenomena at play in LiHo_xY_{1-x}F4, in both zero and nonzero Bx.

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Michel J. P. Gingras, Patrik Henelius. 2011-03-08. Collective Phenomena in the LiHo_xY_{1-x}F4 Quantum Ising Magnet: Recent Progress and Open Questions. https://doi.org/10.1088/1742-6596%2F320%2F1%2F012001

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