• DOI:10.1103/PhysRevA.94.053615
• Corpus ID: 118382289

Quantum critical behavior influenced by measurement backaction in ultracold gases

@article{Ashida2016QuantumCB,
  title={Quantum critical behavior influenced by measurement backaction in ultracold gases},
  author={Yuto Ashida and Shunsuke Furukawa and Masahito Ueda},
  journal={Physical Review A},
  year={2016},
  volume={94},
  pages={053615}
}

• Y. Ashida, S. Furukawa, Masahito Ueda
• Published 23 May 2016
• Physics
• Physical Review A

Recent realizations of quantum gas microscope offer the possibility of continuous monitoring of the dynamics of a quantum many-body system at the single-particle level. By analyzing effective non-Hermitian Hamiltonians of interacting bosons in an optical lattice and continuum, we demonstrate that the backaction of quantum measurement shifts the quantum critical point and gives rise to a unique critical phase beyond the terrain of the standard universality class. We perform mean-field and strong-coupling-expansion analyses and show that non-Hermitian contributions shift the superfluid--to-Mott-insulator transition point. Using a low-energy effective field theory, we discuss critical behavior of the one-dimensional interacting Bose gas subject to the measurement backaction. We derive an exact ground state of the effective non-Hermitian Hamiltonian and find a unique critical behavior beyond the Tomonaga-Luttinger liquid universality class. We propose experimental implementations of post-selections using quantum gas microscopes to simulate the non-Hermitian dynamics and argue that our results can be investigated with current experimental techniques in ultracold atoms.