Probabilistic Nonunitary Gate in Imaginary Time Evolution

Understand

Simulation of quantum matters is a significant application of quantum computers.

• In contrast to the unitary operation which can be realized naturally on a quantum computer, the implementation of nonunitary operation, widely used in classical approaches, needs special designing.
• Here, by application of Grover's algorithm, we extend the probabilistic method of implementing nonunitary operation and show that it can promote success probability without fidelity decreasing.
• This method can be applied to problems of imaginary time evolution and contraction of tensor networks on a quantum computer.