ICTS:30352

Deconfined Quantum Criticality sans Quantum

APA

(2024). Deconfined Quantum Criticality sans Quantum. SciVideos. https://youtube.com/live/Qpn9H87H6Jg

MLA

Deconfined Quantum Criticality sans Quantum. SciVideos, Nov. 26, 2024, https://youtube.com/live/Qpn9H87H6Jg

BibTex

          @misc{ scivideos_ICTS:30352,
            doi = {},
            url = {https://youtube.com/live/Qpn9H87H6Jg},
            author = {},
            keywords = {},
            language = {en},
            title = {Deconfined Quantum Criticality sans Quantum},
            publisher = {},
            year = {2024},
            month = {nov},
            note = {ICTS:30352 see, \url{https://scivideos.org/icts-tifr/30352}}
          }
          
Abhishodh Prakash
Talk numberICTS:30352

Abstract

Spontaneous symmetry breaking underpins some of the most important phenomena in condensed matter and statistical physics. A description of direct transitions between symmetry breaking phases in terms of local order parameters is formulated when the symmetry breaking patterns were Landau-compatible i.e. when the unbroken symmetries of one phase is a subset of the other. About twenty years ago, Senthil et al [1] demonstrated that a direct transition between Landau-incompatible symmetry breaking phases was also possible in two-dimensional quantum magnets. Such 'deconfined quantum critical' (DQC) transitions are believed to be exotic and found in interacting quantum systems, often with anomalous symmetries (e.g.: constrained by Lieb-Schultz-Mattis theorems).

In this talk, based on recent work with N. Jones [2], I will demonstrate that such special conditions are unnecessary and Landau-incompatible transitions can be found in a well-known family of classical statistical mechanical models introduced by Jose, Kadanoff, Kirkpatrick and Nelson [3]. All smoking-gun DQC features such as charged defect melting and enhanced symmetries are present and readily understood. I will also show that a closely related family of models also exhibits another unusual critical phenomenon found in quantum systems- 'unnecessary criticality' where a stable critical surface exists within a single phase of matter analogous to the first-order line separating liquid and gases.

[1] SCIENCE, Vol 303, Issue 5663
[2] arXiv: 2404.19009
[3] Phys. Rev. B 16, 1217 (1977)