Shruti Dogra

Experimental demonstration of robustness under scaling errors for superadiabatic population transfer in a superconducting circuit

  1. Shruti Dogra,
  2. Antti Vepsäläinen,
  3. and Gheorghe Sorin Paraoanu
We study experimentally and theoretically the transfer of population between the ground state and the second excited state in a transmon circuit by the use of superadiabatic stimulated
Raman adiabatic passage (saSTIRAP). We show that the transfer is remarkably resilient against variations in the amplitudes of the pulses (scaling errors), thus demostrating that the superadiabatic process inherits certain robustness features from the adiabatic one. In particular, we put in evidence a new plateau that appears at high values of the counterdiabatic pulse strength, which goes beyond the usual framework of saSTIRAP.
arxiv pdf

Quantum simulation of parity-time symmetry breaking with a superconducting quantum processor

  1. Shruti Dogra,
  2. Artem A. Melnikov,
  3. and Gheorghe Sorin Paraoanu
The observation of genuine quantum effects in systems governed by non-Hermitian Hamiltonians has been an outstanding challenge in the field. Here we simulate the evolution under such
Hamiltonians in the quantum regime on a superconducting quantum processor by using a dilation procedure involving an ancillary qubit. We observe the parity-time ()-symmetry breaking phase transition at the exceptional points, obtain the critical exponent, and show that this transition is associated with a loss of state distinguishability. In a two-qubit setting, we show that the entanglement can be modified by local operations.
arxiv pdf