2018/10/26 by Julia Steinberg, N. P. Armitage, Fabian H. L. Essler +2 · 24 citations
Physics and Astronomy · #Advanced Condensed Matter Physics #Condensed matter physics #Criticality #Fermion #Ising model #Nuclear physics #Phase transition #Physics #Physics of Superconductivity and Magnetism #Quantum #Quantum many-body systems #Quantum mechanics #Quantum phase transition #Quantum phases #Spin (aerodynamics) #Thermodynamics #cond-mat.stat-mech #cond-mat.str-el
paper · pdf · doi:10.1103/physrevb.99.035156
published in Physical review. B./Physical review. B 99(3) (American Physical Society) · 16 pages, 4 figures
arxiv created 2018/10/26 · openalex publication_date 2019/01/29 · arxiv updated 2019/02/06 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
The quantum Ising chain in a transverse magnetic field is t\phantom\rule00exh\phantom\rule00exe paradigm of a quantum phase transition, displaying universal quantum criticality at low temperatures. Insights from this model have informed studies of quantum criticality in numerous modern correlated-electron materials. There have been a number of experimental studies of the quantum Ising chain, most notably in the material CoNb2O6. It has recently become clear that there was a surprising discrepancy between the observations: the energy gap in the quantum disordered regime as measured by nuclear magnetic resonance was approximately twice that measured by other methods. Here, the authors show via careful analysis of the low-temperature excitations that this is not a discrepancy, rather, it is in fact to be expected from the subtle interactions between the excitations. Although the underlying spin excitations are bosonic, their interactions transmute them into fermions, and this is a key ingredient in understanding the experiments.