Laboratoire de Physique Théorique
Toulouse - UMR 5152

I will review in this talk some of my PhD works up to now. I will discuss the temperature dependance of experimentally relevant time-dependent quantities, such as the NMR relaxation rate for quasi-1D magnetic spin systems [1,2]. I will also present the high magnetic field phase diagram of the quasi-one-dimensional S=1 antiferromagnetic material Ni(Cl_1-xBr_x)_2-4SC(NH_2), which exhibits a Bose-Einstein condensation [3]. For x≠0, this compound was believed to provide the first experimental realization of the elusive Bose-glass phase in a quantum magnet. I will review our recent experimental and theoretical works [4-7] in which we discovered that this many-body localized phase is actually undermined by the resurgence of long-range order with a condensation of the underlying impurities degree of freedom, leading to a novel "order-by-disorder" mechanism.

[1] M. Dupont et al. Phys. Rev. B. 94, 144403 (2016)

[2] M. Dupont et al. (work in progress)

[3] R. Blinder et al. Phys. Rev. B 95, 020404(R) (2017)

[4] A. Orlova et al. Phys. Rev. Lett. 118, 067203 (2017)

[5] M. Dupont et al. Phys. Rev. Lett. 118, 067204 (2017)

[6] M. Dupont et al. Phys. Rev. B 96, 024442 (2017)

[7] A. Orlova et al. (manuscript in preparation)