Revealing three-dimensional quantum criticality by Sr substitution in Han purple
Research output: Contribution to journal › Journal article › Research › peer-review
Documents
- PhysRevResearch.3.023177
Final published version, 4 MB, PDF document
Classical and quantum phase transitions (QPTs), with their accompanying concepts of criticality and universality, are a cornerstone of statistical thermodynamics. An excellent example of a controlled QPT is the field-induced ordering of a gapped quantum magnet. Although numerous "quasi-one-dimensional" coupled spin-chain and -ladder materials are known whose ordering transition is three-dimensional (3D), quasi-two-dimensional (2D) systems are special for multiple reasons. Motivated by the ancient pigment Han purple (BaCuSi2O6), a quasi-2D material displaying anomalous critical properties, we present a complete analysis of Ba0.9Sr0.1CuSi2O6. We measure the zero-field magnetic excitations by neutron spectroscopy and deduce the spin Hamiltonian. We probe the field-induced transition by combining magnetization, specific-heat, torque, and magnetocalorimetric measurements with nuclear magnetic resonance studies near the QPT. With a Bayesian statistical analysis and large-scale Quantum Monte Carlo simulations, we demonstrate unambiguously that observable 3D quantum critical scaling is restored by the structural simplification arising from light Sr substitution in Han purple.
Original language | English |
---|---|
Article number | 023177 |
Journal | Physical Review Research |
Volume | 3 |
Issue number | 2 |
Number of pages | 18 |
DOIs | |
Publication status | Published - 4 Jun 2021 |
- BOSE-EINSTEIN CONDENSATION, GROUND-STATE, MAGNETIZATION PLATEAUS, PHASE-TRANSITIONS, FIELD, TEMPERATURE, MODEL, ANTIFERROMAGNET
Research areas
ID: 279186846