Nuclear Magnetic Resonance Reveals Disordered Level-Crossing Physics in the Bose-Glass Regime of the Br-doped Ni(Cl${}_{1-x}$Br${}_x$)${}_2$-4SC(NH${}_2$)${}_2$ Compound at a High Magnetic Field

Abstract

By measuring the nuclear magnetic resonance (NMR) 1/T_1 relaxation rate in the Br (bond) doped DTN compound, Ni(Cl(1-x)Br_x)2-4SC(NH2)2 (DTNX), we show that the low-energy spin dynamics of its high magnetic field "Bose-glass" regime is dominated by a strong peak of spin fluctuations found at the nearly doping-independent position H* = 13.6 T. From its temperature and field dependence we conclude that this corresponds to a level crossing of the energy levels related to the doping-induced impurity states. Observation of the local NMR signal from the spin adjacent to the doped Br allowed us to fully characterize this impurity state. We have thus quantified a microscopic theoretical model that paves the way to better understanding of the Bose-glass physics in DTNX, as revealed in the related theoretical study [M. Dupont, S. Capponi, and N. Laflorencie, Phys. Rev. Lett. 118, 067204 (2017), arXiv:1610.05136].

6 pages, 4 figures

References in corpus (8)

• Bose-Einstein Condensation in Magnetic Insulators
• Localization of preformed Cooper-pairs in disordered superconductors
• The quasi-periodic Bose-Hubbard model and localization in one-dimensional cold atomic gases
• Bose glass and superfuid phases of cavity polaritons
• Similar glassy features in the NMR response of pure and disordered La1.88Sr0.12CuO4
• Critical properties and Bose Einstein Condensation in dimer spin systems
• Nuclear magnetic resonance study of the magnetic-field-induced ordered phase in the NiCl2-4SC(NH2)2 compound
• Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl${}_{1-x}$Br${}_x$)${}_2$-4SC(NH${}_2$)${}_2$ at High Magnetic Fields

Cited by in corpus (6)

• Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl${}_{1-x}$Br${}_x$)${}_2$-4SC(NH${}_2$)${}_2$ at High Magnetic Fields
• Quantum criticality in a three dimensional spin system at zero field and pressure
• Magnetic-field-induced ordered phase in the chloro-bridged copper(II) dimer system [Cu2(apyhist)2Cl2](ClO4)2
• Single crystal growth and study of the magnetic properties of the mixed spin-dimer system Ba${}_{3-x}$Sr${}_x$Cr${}_2$O${}_8$
• Numerical study of the temperature dependence of the NMR relaxation rate across the superfluid-Bose glass transition in one dimension
• Narrowly avoided spin-nematic phase in BaCdVO(PO${}_4$)${}_2$: NMR evidence