Localization-delocalization transition in the dynamics of dipolar-coupled nuclear spins

The dynamics of dipolar interactions Well-controlled systems, such as cold atomic gases, can simulate more complicated materials. Applying this quantum simulation concept to the study of magnetism, Alvarez et al. add an interesting twist. Instead of cold atoms, a network of nuclear spins of hydrogen in polycrystalline adamantane serves as a simulator. Using nuclear magnetic resonance techniques, the authors could induce a transition from a state in which all spins coupled to each other to a state in which coherent spins grouped into clusters. Science, this issue p. 846 Nuclear magnetic resonance techniques are used to simulate the dynamics of dipolar interactions. Nonequilibrium dynamics of many-body systems are important in many scientific fields. Here, we report the experimental observation of a phase transition of the quantum coherent dynamics of a three-dimensional many-spin system with dipolar interactions. Using nuclear magnetic resonance (NMR) on a solid-state system of spins at room-temperature, we quench the interaction Hamiltonian to drive the evolution of the system. Depending on the quench strength, we then observe either localized or extended dynamics of the system coherence. We extract the critical exponents for the localized cluster size of correlated spins and diffusion coefficient around the phase transition separating the localized from the delocalized dynamical regime. These results show that NMR techniques are well suited to studying the nonequilibrium dynamics of complex many-body systems.

[1]  E. Altman,et al.  Many-body localization in one dimension as a dynamical renormalization group fixed point. , 2012, Physical review letters.

[2]  D. F. McMorrow,et al.  Quantum Phase Transition of a Magnet in a Spin Bath , 2005, Science.

[3]  M. Lewenstein,et al.  The physics of dipolar bosonic quantum gases , 2009, 0905.0386.

[4]  Thomas G. Walker,et al.  Quantum information with Rydberg atoms , 2009, 0909.4777.

[5]  D. Suter,et al.  Quantum simulations of localization effects with dipolar interactions , 2013, 1305.2526.

[6]  Alexey V. Gorshkov,et al.  Non-local propagation of correlations in quantum systems with long-range interactions , 2014, Nature.

[7]  F. Nori,et al.  Quantum Simulation , 2013, Quantum Atom Optics.

[8]  A. Aspect,et al.  Three-dimensional localization of ultracold atoms in an optical disordered potential , 2011, Nature Physics.

[9]  M. Rigol,et al.  Thermalization and its mechanism for generic isolated quantum systems , 2007, Nature.

[10]  D. Basko,et al.  Metal–insulator transition in a weakly interacting many-electron system with localized single-particle states , 2005, cond-mat/0506617.

[11]  Jun Ye,et al.  Observation of dipolar spin-exchange interactions with lattice-confined polar molecules , 2013, Nature.

[12]  J. Dalibard,et al.  Many-Body Physics with Ultracold Gases , 2007, 0704.3011.

[13]  J. Eisert,et al.  Probing the relaxation towards equilibrium in an isolated strongly correlated one-dimensional Bose gas , 2011, Nature Physics.

[14]  Markus Greiner,et al.  A quantum gas microscope for detecting single atoms in a Hubbard-regime optical lattice , 2009, Nature.

[15]  M. Inguscio,et al.  Measurement of the mobility edge for 3D Anderson localization , 2014, Nature Physics.

[16]  V. Vedral,et al.  Entanglement in many-body systems , 2007, quant-ph/0703044.

[17]  Warren S. Warren,et al.  Selective Excitation of Multiple-Quantum Coherence in Nuclear Magnetic Resonance , 1979 .

[18]  A. Pines,et al.  Multiple‐quantum dynamics in solid state NMR , 1985 .

[19]  S. Lacelle.  On the Growth of Multiple Spin Coherences in NMR of Solids , 1991 .

[20]  C. F. Roos,et al.  Entanglement growth in quench dynamics with variable range interactions , 2013, 1305.6880.

[21]  D. Suter,et al.  NMR quantum simulation of localization effects induced by decoherence. , 2010, Physical review letters.

[22]  B. Lanyon,et al.  Quasiparticle engineering and entanglement propagation in a quantum many-body system , 2014, Nature.

[23]  D. Huse,et al.  Localization of interacting fermions at high temperature , 2006, cond-mat/0610854.

[24]  Y. Wang,et al.  Quantum error correction in a solid-state hybrid spin register , 2013, Nature.

[25]  J. Schmiedmayer,et al.  Non-equilibrium coherence dynamics in one-dimensional Bose gases. , 2007, Nature.

[26]  P. Anderson.  Local moments and localized states , 1978 .

[27]  Julien Chabé,et al.  Experimental observation of the Anderson metal-insulator transition with atomic matter waves. , 2007, Physical review letters.

[28]  G. Aeppli,et al.  Dipolar Antiferromagnetism and Quantum Criticality in LiErF4 , 2012, Science.

[29]  J. Klafter,et al.  The random walk's guide to anomalous diffusion: a fractional dynamics approach , 2000 .

[30]  P. Szriftgiser,et al.  Observation of the Anderson metal-insulator transition with atomic matter waves: Theory and experiment , 2009, 0907.3411.

[31]  Immanuel Bloch,et al.  Light-cone-like spreading of correlations in a quantum many-body system , 2011, Nature.

[32]  Magnetic dipolar ordering and quantum phase transition in an Fe8 molecular magnet. , 2011, Physical review letters.

[33]  F. Wegner.  Electrons in disordered systems. Scaling near the mobility edge , 1976 .