ELFT HÍRADÓ

[Janos Asboth <asboth.janos AT ttk.bme.hu>]

Meghívó

BME Elméleti Fizika Szeminárium,

feb. 28. péntek 10h15,
1111 Bp., Budafoki út 8., BME FIII. magasföldszint 1, szemináriumi szoba

Rakovszky Tibor (BME Elm. Fiz. tanszék):
Entanglement, topological order and glassiness in finite temperature
quantum phases

In recent decades, one of the central goals of condensed matter physics has
been the classification and characterization of quantum phases of matter at
zero temperature. This has led to the discovery of many exotic phases,
notable those exhibiting topological order, characterized by long-range
quantum entanglement and a ground state degeneracy that depends on the
underlying topology. Much less is known about the situation at finite,
non-zero temperatures; for example no examples of finite temperature
topological order exist in spatial dimensions below 4.

In this talk, I will discuss a series of results [1-3] relevant to the
problem of quantum phases at nonzero temperatures. First, I will discuss a
theorem that provides a "dynamical" perspective on finite temperature
phases, relating them to open system dynamics. As an application of this
perspective, I will discuss a family of spatially non-local models that
exhibit a new kind of "topological quantum spin glass", combining quantum
topological order, with features of classical mean-field spin glasses.
Finally, I will discuss a model that realizes quantum topological order in
3 spatial dimensions for the first time.

References:
[1]: Bottlenecks in quantum channels and finite temperature phases of
matter,
https://arxiv.org/abs/2412.09598
[2]: Topological Quantum Spin Glass Order and its realization in qLDPC
codes,
https://arxiv.org/abs/2412.13248
[3]: Finite-temperature quantum topological order in three dimensions,
https://arxiv.org/abs/2503.02928

Minden érdeklődőt szeretettel várunk.
Asbóth János,
 szemináriumi koordinátor