Dynamics in many-body localized quantum systems without disorder

Schiulaz, Mauro; Silva, Alessandro; Müller, Markus

doi:10.1103/physrevb.91.184202

Cited by 138 publications

(130 citation statements)

References 46 publications

Supporting

Mentioning

128

Contrasting

Order By: Relevance

“…37) contradicts the predicted dynamics of both DSIM and MMSI models (39). Instead, one intriguing possibility is that the state of Dy 2 Ti 2 O 7 actually represents translationally invariant many-body localization of the spins (42)(43)(44). It will be fascinating, in this context, to reconsider the absence of magnetic ordering in other frustrated pyrochlores so as to determine if supercooled classical spin liquids occur therein.…”

Section: Conclusion and Discussionmentioning

confidence: 90%

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇

Kassner

Eyvazov

Pichler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

A "supercooled" liquid develops when a fluid does not crystallize upon cooling below its ordering temperature. Instead, the microscopic relaxation times diverge so rapidly that, upon further cooling, equilibration eventually becomes impossible and glass formation occurs. Classic supercooled liquids exhibit specific identifiers including microscopic relaxation times diverging on a Vogel-TammannFulcher (VTF) trajectory, a Havriliak-Negami (HN) form for the dielectric function e(ω, T ), and a general Kohlrausch-Williams-Watts (KWW) form for time-domain relaxation. Recently, the pyrochlore Dy 2 Ti 2 O 7 has become of interest because its frustrated magnetic interactions may, in theory, lead to highly exotic magnetic fluids. However, its true magnetic state at low temperatures has proven very difficult to identify unambiguously. Here, we introduce highprecision, boundary-free magnetization transport techniques based upon toroidal geometries and gain an improved understanding of the time-and frequency-dependent magnetization dynamics of Dy 2 Ti 2 O 7 . We demonstrate a virtually universal HN form for the magnetic susceptibility χ (ω, T ), a general KWW form for the realtime magnetic relaxation, and a divergence of the microscopic magnetic relaxation rates with the VTF trajectory. Low-temperature Dy 2 Ti 2 O 7 therefore exhibits the characteristics of a supercooled magnetic liquid. One implication is that this translationally invariant lattice of strongly correlated spins may be evolving toward an unprecedented magnetic glass state, perhaps due to many-body localization of spin.spin liquid | supercooled liquids | magnetic dynamics | periodic boundaries C ooling a pure liquid usually results in crystallization via a first-order phase transition. However, in glass-forming liquids when the cooling is sufficiently rapid, a metastable "supercooled" state is achieved instead (1-3). Here, the microscopic relaxation times diverge until equilibration of the system is no longer possible at a given cooling rate. At this juncture there is generally a broad peak in the specific heat preceding the glass transition, at which no symmetry-breaking phase transition occurs (Fig. 1A). The antecedent fluid exhibits a set of phenomena characteristic of the supercooled liquid state (1-3). For example, the divergence of microscopic relaxation times τ 0 ðTÞ typically shows substantial departures from Arrhenius behavior [τ 0 ðTÞ = AexpðΔ=kTÞ and, instead, is described characteristically using the Vogel-Tammann-Fulcher (VTF) form (4)Here, T 0 is a temperature at which the relaxation time diverges to ∞ while D characterizes the extent of the super-Arrhenius behavior (Fig. 1B). One way to establish τ 0 ðTÞ is by measuring the characteristic frequency ω 0 ðTÞ = 1=τ 0 ðTÞ of peaks in the dissipative (imaginary) component of the dielectric function «ðω, TÞ.For classic supercooled liquids, «ðω, TÞ generally exhibits the Havriliak-Negami (HN) form (5, 6) «ðω,[2]Here, the exponents α and γ describe, respectively, the broadening and asymmetry of the rela...

show abstract

Section: Conclusion and Discussionmentioning

confidence: 90%

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇

Kassner

Eyvazov

Pichler

et al. 2015

Proc. Natl. Acad. Sci. U.S.A.

View full text Add to dashboard Cite

show abstract

“…A number of numerical studies of translationally invariant systems with no quenched disorder have been carried out. However, due to large finite size effects these studies are inconclusive with respect to localization [13][14][15][16][17][18][19][20]. A related question, whether MBL can exist in a system where only some of the single-particle states are delocalized, namely in systems with a mobility edge in the singleparticle spectrum, has been affirmatively answered [21][22][23][24].…”

mentioning

confidence: 99%

Many-body localization in system with a completely delocalized single-particle spectrum

2016

View full text Add to dashboard Cite

Many-body localization (MBL) in a one-dimensional Fermi Hubbard model with random on-site interactions is studied. While for this model all single-particle states are trivially delocalized, it is shown that for sufficiently strong disordered interactions the model is many-body localized. It is therefore argued that MBL does not necessary rely on localization of the single-particle spectrum. This model provides a convenient platform to study pure MBL phenomenology, since Anderson localization in this model does not exist. By examining various forms of the interaction term a dramatic effect of symmetries on charge transport is demonstrated. A possible realization in a cold atom experiments is proposed. Introduction.-It has been known for almost 60 years that non-interacting particles in one-dimensional disordered systems exhibit Anderson localization [1]. Transport in these systems is exponentially suppressed with the system size, and without coupling to the environment, these systems are non-ergodic at any temperature. Anderson localized systems are, however, non-generic, since they do not include interactions which allow for the exchange of energy. For many years it was assumed that interactions generally restore ergodicity and destroy localization [2]. A decade ago, using non-equilibrium diagrammatic techniques, it was argued that Anderson localization is stable under the addition of a small shortranged interactions [3], a phenomenon currently known as many-body localization (MBL). Many-body localized systems are the only known generic non-ergodic systems which do not follow the assumptions of statistical mechanics [4][5][6]. While the realization of MBL systems presents challenges in condensed matter systems due to inevitable presence of phonons [7,8], recent experiments in cold atoms have provided evidence of the existence of MBL in both one-dimensional [9-11] and two-dimensional systems [12].

show abstract

“…Examples of interesting problems that can be probed in experiments with molecules or excitations in optical lattices include interaction-induced many-body localization (e.g., can many-body localization happen without disorder?) [36] or interaction-induced delocalization of quantum particles in disordered potentials [37][38][39][40][41][42].…”

Section: Introductionmentioning

confidence: 99%

Effects of long-range hopping and interactions on quantum walks in ordered and disordered lattices

Chattaraj

Krems

2016

Phys. Rev. A

View full text Add to dashboard Cite

We study the effects of long-range hopping and long-range inter-particle interactions on quantum walk of hard-core bosons in ideal and disordered one-dimensional lattices. We find that the range of hopping has a much more significant effect on the particle correlation dynamics than the range of interactions. We illustrate that long-range hopping makes the correlation diagrams asymmetric with respect to the sign of the interaction and examine the relative role of repulsive and attractive interactions on the dynamics of scattering by isolated impurities and Anderson localization in disordered lattices. We show that weakly repulsive interactions increase the probability of tunnelling through isolated impurities and decrease the localization.

show abstract

Dynamics in many-body localized quantum systems without disorder

Cited by 138 publications

References 46 publications

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇

Many-body localization in system with a completely delocalized single-particle spectrum

Effects of long-range hopping and interactions on quantum walks in ordered and disordered lattices

Contact Info

Product

Resources

About

Dynamics in many-body localized quantum systems without disorder

Cited by 138 publications

References 46 publications

Supercooled spin liquid state in the frustrated pyrochlore Dy 2 Ti 2 O 7

Supercooled spin liquid state in the frustrated pyrochlore Dy 2 Ti 2 O 7

Many-body localization in system with a completely delocalized single-particle spectrum

Effects of long-range hopping and interactions on quantum walks in ordered and disordered lattices

Contact Info

Product

Resources

About

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇

Supercooled spin liquid state in the frustrated pyrochlore Dy ₂ Ti ₂ O ₇