Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl$_{1-x}$Br$_x$)$_2$-4SC(NH$_2$)$_2$ at High Magnetic Fields

Maxime Dupont; Sylvain Capponi; Nicolas Laflorencie

doi:10.1103/PhysRevLett.118.067204

paper

Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ -4SC(NH $_{2}$ ) $_{2}$ at High Magnetic Fields

arXiv:1610.05136 · doi:10.1103/PhysRevLett.118.067204

Abstract

Building on recent NMR experiments [Phys. Rev. Lett. 118, 067203], we theoretically investigate the high magnetic field regime of the disordered quasi-one-dimensional $S = 1$ antiferromagnetic material Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ -4SC(NH $_{2}$ ) $_{2}$ . The interplay between disorder, chemically controlled by Br-doping, interactions, and the external magnetic field, leads to a very rich phase diagram. Beyond the well-known antiferromagnetically ordered regime, analog of a Bose condensate of magnons, which disappears when $H \geq 12.3$ T, we unveil a resurgence of phase coherence at higher field $H \sim 13.6$ T, induced by the doping. Interchain couplings stabilize finite temperature long-range order whose extension in the field - temperature space is governed by the concentration of impurities $x$ . Such a "mini-condensation" contrasts with previously reported Bose-glass physics in the same regime, and should be accessible to experiments.

6 pages, 4 figures

Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl $_{1 - x}$ Br $_{x}$ ) $_{2}$ -4SC(NH $_{2}$ ) $_{2}$ at High Magnetic Fields

Abstract

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Disorder-induced Revival of the Bose-Einstein Condensation in Ni(Cl1−x​Brx​)2​-4SC(NH2​)2​ at High Magnetic Fields

Abstract

References in corpus (12)

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