Unusual magnetic field-dependence of a possible hidden order phase
| Autor: | Peter S. Riseborough, E. J. Calegari, S. G. Magalhaes |
|---|---|
| Jazyk: | angličtina |
| Rok vydání: | 2017 |
| Předmět: |
Physics
Quantum phase transition Phase transition Field (physics) Condensed matter physics Transformações de fase Phase (waves) 02 engineering and technology Quantum phases 021001 nanoscience & nanotechnology Condensed Matter Physics Anisotropia magnética lcsh:Atomic physics. Constitution and properties of matter 01 natural sciences Magnetic susceptibility Electronic Optical and Magnetic Materials lcsh:QC170-197 Sistemas de férmions pesados 0103 physical sciences lcsh:TA401-492 Spin density wave lcsh:Materials of engineering and construction. Mechanics of materials 010306 general physics 0210 nano-technology Lattice model (physics) |
| Zdroj: | npj Quantum Materials, Vol 2, Iss 1, Pp 1-9 (2017) Repositório Institucional da UFRGS Universidade Federal do Rio Grande do Sul (UFRGS) instacron:UFRGS |
| ISSN: | 2397-4648 |
| DOI: | 10.1038/s41535-017-0055-2 |
| Popis: | URu2Si2 exhibits a second-order phase transition at 17.5 K. Initially it was thought that the transition was to a spin density wave phase, however, subsequent measurements do not support this assignment. Despite the unknown nature of the order parameter, many experimental results can be described in terms of the formation of a generic density wave. Here, we report calculations on an unusual phase of the underscreened Anderson lattice model, the so called spin-dependent inter-orbital density wave that has been proposed as describing the “hidden order” phase of URu2Si2. We determine the effects of an applied magnetic field. Since the order parameter describes an ordering in the x–y plane, the electronic properties of the system are anisotropic below the critical temperature T HO. We show that the magnetic susceptibility becomes anisotropic below T HO. Furthermore, for fields applied along a spontaneously chosen hard axis, T HO decreases towards zero and that the HO transition changes from second order to first order at a large value of the magnetic field. Also, we find that the system undergoes a cascade of field-induced Lifshitz transitions and also show how these properties originate from the dependence of the quasi-particle bands on the orientation of the applied field. The good qualitative agreement with experimental findings provides strong support for the proposed description of the HO phase as a spin-dependent inter-orbital density wave phase. Support for an explanation of a quantum phase that has remained mysterious for decades is provided by researchers in Brazil and the USA. Peter Riseborough from Temple University and colleagues determine the magnetic properties of a model proposed to describe the so-called ‘hidden order’. Macroscopic signatures of quantum phases are identifiable in experiments but the underlying microscopic origin is not always clear. One prominent example is uranium ruthenium silicide, which exhibits ordering below a temperature of 17.5 Kelvin. It is known that an applied pressure induces a phase change and yet, contradictorily, experiments indicate that there is no structural change. The team show that one model proposed to solve this problem, the underscreened Anderson lattice model, gives rise to an anisotropic magnetic susceptibility. This agrees with experimental results and provides strong backing for the model. |
| Databáze: | OpenAIRE |
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