scholarly journals Controllable quantum spin glasses with magnetic impurities embedded in quantum solids

2013 ◽  
Vol 88 (1) ◽  
Author(s):  
Mikhail Lemeshko ◽  
Norman Y. Yao ◽  
Alexey V. Gorshkov ◽  
Hendrik Weimer ◽  
Steven D. Bennett ◽  
...  
Keyword(s):  
Spin Glasses ◽  
Quantum Spin ◽  
Quantum Solids ◽  
Magnetic Impurities

scholarly journals Conduction Electron Scattering in Alloys

1986 ◽  
Vol 39 (4) ◽  
pp. 529 ◽  
Author(s):  
PL Rossiter
Keyword(s):  
Relaxation Time ◽  
Conduction Electron ◽  
Spin Glasses ◽  
Spin Fluctuation ◽  
Mean Free Path ◽  
Spin Fluctuations ◽  
Blocking Temperature ◽  
Magnetic Impurities ◽  
Magnetic Clusters ◽  
Electron Mean Free Path

The aim of this review is to present a simple physical picture which shows how the electrical resistivity of a system depends upon the spatial extent and lifetime of the scattering disturbance measured in relation to the conduction electron mean free path and relaxation time. The contribution from spin fluctuations associated with isolated magnetic impurities is discussed on the basis of this model and it is shown that at temperatures below the characteristic spin fluctuation temperature the impurity acts as though it were nonmagnetic. Some results are given for both 'Kondo' (Anderson) and exchange enhanced (Wolfi) systems. Spin glasses are also discussed and the resistivity behaviour is shown to result from a competition between the RKKY interaction and spin fluctuation effects. Ordered magnetic clusters are shown to be static for periods comparable with the conduction electron relaxation time, so that there is no resistivity anomaly expected at the superparamagnetic blocking temperature. The observed temperature dependence of the resistivity then follows simply from the change in magnetic correlations within the cluster.

scholarly journals Ergodic and localized regions in quantum spin glasses on the Bethe lattice

2017 ◽  
Vol 375 (2108) ◽  
pp. 20160424 ◽  
Author(s):  
G. Mossi ◽  
A. Scardicchio
Keyword(s):  
Spin Glass ◽  
Spin Glasses ◽  
Quantum Dynamics ◽  
Bethe Lattice ◽  
Transverse Field ◽  
Quantum Systems ◽  
Quantum Spin ◽  
Many Body ◽  
Spin Glass Phase ◽  
Ising Spin

By considering the quantum dynamics of a transverse-field Ising spin glass on the Bethe lattice, we find the existence of a many-body localized (MBL) region at small transverse field and low temperature. The region is located within the thermodynamic spin glass phase. Accordingly, we conjecture that quantum dynamics inside the glassy region is split into a small MBL region and a large delocalized (but not necessarily ergodic) region. This has implications for the analysis of the performance of quantum adiabatic algorithms. This article is part of the themed issue ‘Breakdown of ergodicity in quantum systems: from solids to synthetic matter’.

scholarly journals Clustering of Nonergodic Eigenstates in Quantum Spin Glasses

2017 ◽  
Vol 118 (12) ◽  
Author(s):  
C. L. Baldwin ◽  
C. R. Laumann ◽  
A. Pal ◽  
A. Scardicchio
Keyword(s):  
Spin Glasses ◽  
Quantum Spin

scholarly journals Self-induced spin glass state in elemental and crystalline neodymium

Science ◽  
2020 ◽  
Vol 368 (6494) ◽  
pp. eaay6757 ◽  
Author(s):  
Umut Kamber ◽  
Anders Bergman ◽  
Andreas Eich ◽  
Diana Iuşan ◽  
Manuel Steinbrecher ◽  
...  
Keyword(s):  
Spin Glass ◽  
Spin Glasses ◽  
Quantum Spin ◽  
Atomic Scale ◽  
Spin Glass State ◽  
Scanning Tunneling ◽  
Spin Frustration ◽  
Tunneling Microscopy ◽  
Glass State ◽  
Aging Phenomena

Spin glasses are a highly complex magnetic state of matter intricately linked to spin frustration and structural disorder. They exhibit no long-range order and exude aging phenomena, distinguishing them from quantum spin liquids. We report a previously unknown type of spin glass state, the spin-Q glass, observable in bulk-like crystalline metallic neodymium thick films. Using spin-polarized scanning tunneling microscopy combined with ab initio calculations and atomistic spin-dynamics simulations, we visualized the variations in atomic-scale noncolinear order and its response to magnetic field and temperature. We quantified the aging phenomena relating the glassiness to crystalline symmetry and the energy landscape. This result not only resolves the long-standing debate of the magnetism of neodymium, but also suggests that glassiness may arise in other magnetic solids lacking extrinsic disorder.

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