Circuit complexity in interacting QFTs and RG flows

Aug 9, 2018
50 pages
Published in:
  • JHEP 10 (2018) 140
  • Published: Oct 23, 2018
e-Print:
DOI:
Report number:
  • YITP-18-89

Citations per year

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Abstract: (Springer)
We consider circuit complexity in certain interacting scalar quantum field theories, mainly focusing on the ϕ4^{4} theory. We work out the circuit complexity for evolving from a nearly Gaussian unentangled reference state to the entangled ground state of the theory. Our approach uses Nielsen’s geometric method, which translates into working out the geodesic equation arising from a certain cost functional. We present a general method, making use of integral transforms, to do the required lattice sums analytically and give explicit expressions for the d = 2, 3 cases. Our method enables a study of circuit complexity in the epsilon expansion for the Wilson-Fisher fixed point. We find that with increasing dimensionality the circuit depth increases in the presence of the ϕ4^{4} interaction eventually causing the perturbative calculation to breakdown. We discuss how circuit complexity relates with the renormalization group.
Note:
  • 50 pages, 2 figures; references updated; version to appear in JHEP
  • Effective Field Theories
  • Lattice Quantum Field Theory
  • Renormalization Group
  • AdS-CFT Correspondence
  • field theory: interaction
  • interaction: scalar
  • field theory: scalar
  • renormalization group: flow
  • epsilon expansion
  • ground state