Revealing three-dimensional quantum criticality by Sr-substitution in Han Purple

Abstract

Classical and quantum phase transitions (QPTs), with their accompanying concepts of criticality and universality, are a cornerstone of statistical thermodynamics. An exemplary controlled QPT is the field-induced magnetic 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-2D systems are special for several physical reasons. Motivated by the ancient pigment Han Purple (BaCuSi${}_2$O${}_6$), a quasi-2D material displaying anomalous critical properties, we present a complete analysis of Ba${}_{0.9}$Sr${}_{0.1}$CuSi${}_2$O${}_6$. We measure the zero-field magnetic excitations by neutron spectroscopy and deduce the magnetic Hamiltonian. We probe the field-induced transition by combining magnetization, specific-heat, torque and magnetocalorimetric measurements with low-temperature nuclear magnetic resonance studies near the QPT. By 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.

19 pages, 5 figures

References in corpus (19)

• Bose-Einstein Condensation in Magnetic Insulators
• Dimensional reduction at a quantum critical point
• Controlling Luttinger liquid physics in spin ladders under a magnetic field
• Hall effect of triplons in a dimerized quantum magnet
• Field-Controlled Magnetic Order in the Quantum Spin-Ladder System (Hpip)2CuBr4
• Incomplete devil's staircase in the magnetization curve of SrCu2(BO3)2
• Bose-Einstein Condensation of Triplons in Ba3Cr2O8
• Multiple Magnon Modes and Consequences for the Bose-Einstein Condensed Phase in BaCuSi2O6
• A Novel Ordered Phase in SrCu2(BO3)2 under High Pressure
• Weakly coupled $s=1/2$ quantum spin singlets in Ba${}_3$Cr${}_2$O${}_8$
• Theory of the field-induced BEC in the frustrated spin-1/2 dimer compound BaCuSi2O6
• NMR evidence for a strong modulation of the Bose-Einstein Condensate in BaCuSi${}_2$O${}_6$
• Nuclear Magnetic Resonance in High Magnetic Field: Application to Condensed Matter Physics
• Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in the NiCl2-4SC(NH2)2 compound
• High-resolution Calorimetry in Pulsed Magnetic Fields
• Dimensional modulation of spontaneous magnetic order in quasi-two-dimensional quantum antiferromagnets
• Two types of adjacent dimer layers in the low temperature phase of BaCuSi2O6
• Crystal growth with oxygen partial pressure of the $BaCuS{i}_2{O}_6$ and $B{a}_{1-x}S{r}_{x}CuS{i}_2{O}_6$ spin dimer compounds
• Floating Zone Growth of Sr Substituted Han Purple: Ba${}_{0.9}$Sr${}_{0.1}$CuSi${}_2$O${}_6$

Cited by in corpus (4)

• Proximate deconfined quantum critical point in SrCu2(BO3)2
• Extending MIEZE spectroscopy towards thermal wavelengths
• Investigating field-induced magnetic order in Han Purple by neutron scattering up to 25.9 T
• Critical Berezinskii-Kosterlitz-Thouless dynamics in the archetypal two-dimensional spin system Ba${}_2$CuSi${}_2$O${}_6$Cl${}_2$