Generalization of group-theoretic coherent states for variational calculations

Publikation: Bidrag til tidsskriftTidsskriftartikelForskningfagfællebedømt


  • Tommaso Guaita
  • Lucas Hackl
  • Tao Shi
  • Eugene Demler
  • J. Ignacio Cirac

We introduce families of pure quantum states that are constructed on top of the well-known Gilmore-Perelomov group-theoretic coherent states. We do this by constructing unitaries as the exponential of operators quadratic in Cartan subalgebra elements and by applying these unitaries to regular group-theoretic coherent states. This enables us to generate entanglement not found in the coherent states themselves, while retaining many of their desirable properties. Most importantly, we explain how the expectation values of physical observables can be evaluated efficiently. Examples include generalized spin-coherent states and generalized Gaussian states, but our construction can be applied to any Lie group represented on the Hilbert space of a quantum system. We comment on their applicability as variational families in condensed matter physics and quantum information.

TidsskriftPhysical Review Research
Udgave nummer2
Antal sider17
StatusUdgivet - 3 maj 2021

Bibliografisk note

Funding Information:
We wish to thank Dr. J. E. Dumont and Dr. C. Delcroix for their stimulating and helpful discussions. We also thank Mrs. D. Legrand for her careful preparation of the manuscript. Work realized under Contract of the Minist~re de la Politique Scientifique within the framework of the Association Euratom--University of Brussels--University of Pisa.

Publisher Copyright:
© 2021 authors.

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