2000/04/05 by N. Harrison, Luis Balicas, L. Balicas +2 · 2 citations
Materials Science · Physics and Astronomy · #Organic and Molecular Conductors Research #Physics of Superconductivity and Magnetism #Quantum and electron transport phenomena #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.62.14212
arxiv created 2000/04/05 · openalex publication_date 2000/12/01 · arxiv updated 2009/11/30 · openalex created_date 2016/06/24 · openalex updated_date 2026/07/28
We present the results of magnetotransport and magnetic torque measurements on the \ensuremathα\ensuremath-(BEDT\ensuremath-TTF)2KHg(SCN)4 charge-transfer salt within its high-magnetic-field phase, in magnetic fields extending to 33 T and temperatures as low as 27 mK. While the experimentally determined phase diagram closely resembles that predicted by theoretical models for charge-density waves in strong magnetic fields, the phase that occurs at fields above \ensuremath∼23 T, which is expected to be either a modulated charge-density wave phase or a charge/spin-density wave hybrid, exhibits unusual physical properties that are most atypical of a density wave ground state. Notably, the resistivity undergoes a dramatic drop below \ensuremath∼3 K within this phase, falling in an approximately exponential fashion at low temperatures, while the magnetic torque undergoes extensive hysteresis. This hysteresis, which occurs over a broad range of fields and gives rise to a large negative differential susceptibility \ensuremath∂M/\ensuremath∂B on reversing the direction of sweep of the magnetic field, is strongly temperature dependent and also has several of the physical characteristics predicted by critical-state models normally used to describe the pinning of vortices in type II superconductors. Such a behavior appears therefore only to be explained consistently in terms of persistent currents within the high-magnetic-field phase of \ensuremathα\ensuremath-(BEDT\ensuremath-TTF)2KHg(SCN)4, although the origin of these currents remains an open question.