日時
2018年4月27日14:30 - 17:30 (JST)
講演者
Dr. Aron Beekman (慶應義塾大学) Edit
会場
言語
英語

In the study of zero-temperature quantum phase transitions, instead of looking how symmetry is broken, it is often useful to see how symmetry can be restored by the condensation of topological defects. Through a duality mapping, Nambu-Goldstone modes are represented as gauge bosons, mediating long-range interactions between topological defects. When the latter condense, those bosons get as mass via the Anderson-Higgs mechanism, which signals the loss of rigidity and the restoration of symmetry.

I will first review the best-studied case: the 2+1D superfluid-insulator transitions where the defects are U(1) vortices. Consecutively several extensions are discussed: going to 3+1D where the defects are not point particles but strings, and quantum elasticity, which studies breaking of spatial translations and rotations.

References

  1. S. Sachev, Harvard University lecture notes
  2. A.J. Beekman, D. Sadri and J. Zaanen: New. J. Phys. 13:033004 (2011) arXiv:1006.2267
  3. A.J. Beekman et al.: Physics Reports 683,1 (2017) arXiv:1603.04254
  4. A.J. Beekman, J. Nissinen, K. Wu, J. Zaanen: Physical Review B 96, 1651115 (2017) arXiv:1703.03157