Nonadiabatic geometric quantum computation in non-Hermitian systems

Nonadiabatic geometric quantum computation (NGQC) has emerged as an excellent proposal for achieving fast and robust quantum control against control errors. However, previous NGQC protocols could not be strongly resilient against the noise from decay of bare states in a realistic system, which can be equivalently described by a non-Hermitian Hamiltonian. Here we show how to perform NGQC in non-Hermitian quantum systems. By utilizing a geometric phase generated by nonunitary evolution of the system, a universal set of geometric gates can be realized with a high fidelity. Moreover, we demonstrate that the nonadiabatic process does not lead to the loss of fidelity from decay.