Nuclear Magnetic Resonance Reveals Disordered Level-Crossing Physics in the Bose-Glass Regime of the Br-Doped Ni(Cl1−xBrx)2−4SC(NH2)2 Compound at a High Magnetic Field

Anna Orlova (1) , Rémi Blinder (1) , Edwin Kermarrec (1) , Maxime Dupont (2, 3) , Nicolas Laflorencie (2, 3) , Sylvain Capponi (2, 3) , Hadrien Mayaffre (1) , Claude Berthier (1) , Armando Paduan-Filho (4) , Mladen Horvatić (1)

1 LNCMI-G - Laboratoire national des champs magnétiques intenses - Grenoble
2 FFC - Fermions Fortement Corrélés (LPT)
3 LPT - Laboratoire de Physique Théorique
4 IFUSP - Instituto de Fisica da Universidade de São Paulo

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].

Domaines: Electrons fortement corrélés [cond-mat.str-el]

Anna Orlova, Rémi Blinder, Edwin Kermarrec, Maxime Dupont, Nicolas Laflorencie, et al.. Nuclear Magnetic Resonance Reveals Disordered Level-Crossing Physics in the Bose-Glass Regime of the Br-Doped Ni(Cl1−xBrx)2−4SC(NH2)2 Compound at a High Magnetic Field. Physical Review Letters, 2017, 118 (6), pp.067203. ⟨10.1103/PhysRevLett.118.067203⟩. ⟨hal-01478853⟩