/biz/ - Business & Finance

>>19735219
>Our findings suggest several directions for investigating time reversal and the backward time flow in real quantum systems. One of the directions to pursue, is the time dependence of the reversal complexity N of an evolving
quantum state.

interesting
they are essentially saying that there is a time dependence based on the reversal complexity (labelled "N") of an evolving quantum state.

they actually mirror exactly what I said about "testing" a quantum computer by reversing the computation in time

On a practical side the time-reversal procedure might be helpful for the quantum program testing. Having in hands a multi-qubit quantum computer it is hard to verify that it really has
computed the desired result. Indeed, the full tomography of the computed state is an exponentially hard task. Alternatively, making the time-reversal of the anticipated computed state and running the same evolution drives
the computer back to its initial state if and only if the computer really made a correct computation. The initial state is typically non-entangled and therefore its verification is an easy task.