Disorder-Induced Revival of the Bose-Einstein Condensation inNi(Cl1−xBrx)2−4SC(NH2)2at High Magnetic Fields
Skip to main content
eScholarship
Open Access Publications from the University of California

Disorder-Induced Revival of the Bose-Einstein Condensation inNi(Cl1−xBrx)2−4SC(NH2)2at High Magnetic Fields

  • Author(s): Dupont, Maxime
  • Capponi, Sylvain
  • Laflorencie, Nicolas
  • et al.
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 $H\ge 12.3$ 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.

Main Content
Current View