Abstract
Eigenstate thermalization is widely accepted as the mechanism behind thermalization in generic isolated quantum systems. Using the example of a single magnetic defect embedded in the integrable spin-1/2 XXZ chain, we show that locally perturbing an integrable system can give rise to eigenstate thermalization. Unique to such setups is the fact that thermodynamic and transport properties of the unperturbed integrable chain emerge in properties of the eigenstates of the perturbed (nonintegrable) one. Specifically, we show that the diagonal matrix elements of observables in the perturbed eigenstates follow the microcanonical predictions for the integrable model, and that the ballistic character of spin transport in the integrable model is manifest in the behavior of the off-diagonal matrix elements of the current operator in the perturbed eigenstates.
| Original language | English |
|---|---|
| Article number | 070605 |
| Journal | Physical Review Letters |
| Volume | 125 |
| Issue number | 7 |
| DOIs | |
| State | Published - Aug 14 2020 |
Funding
This work was supported by the European Research Council Starting Grant ODYSSEY Grant No. 758403 (M.\u2009B. and J.\u2009G.), the Royal Society (M.\u2009B.), a SFI-Royal Society University Research Fellowship (J.\u2009G.), and the National Science Foundation Grant No. PHY-1707482 (T.\u2009L. and M.\u2009R.). M.\u2009B. and J.\u2009G. acknowledge the DJEI/DES/SFI/HEA Irish Centre for High-End Computing (ICHEC) for the provision of computational facilities and support, Project No. TCPHY118B, and the Trinity Centre for High-Performance Computing.