2024/09/17 by Davani, Siavash, Eilenberger, Falk
#Applied Physics (physics.app-ph) #Computational Physics (physics.comp-ph) #FOS: Physical sciences #Quantum Physics (quant-ph)
paper · doi:10.48550/arxiv.2409.11020
Given an operator that produces the state |ϕ⟩=∑ϕ(x) |x⟩, we propose a quantum protocol that transforms any input state of the form |ψ⟩=∑ψ(x) |x⟩ to |ψ'⟩=∑ψ(x) eiα|ϕ(x)|2 |x⟩. This protocol is thus programmable in the sense that one can use it to apply different phase profiles eiα|ϕ(x)|2 by choosing different |ϕ⟩ states as the input parameter at each run. Therefore, the problem of applying phases to a signal via a quantum computer is reduced to the problem of initializing a state |ϕ⟩ that corresponds to the desired phase profile. Furthermore, we discuss possible applications of this protocol, most importantly in Hamiltonian simulation.