arXiv subjects

Jian-jian Cheng

Publications and source records attributed to Jian-jian Cheng.

2 recordsLinked to original sources

arXiv2021

Implementing conventional and unconventional nonadiabatic geometric quantum gates via SU(2) transformations

We propose a simple but versatile protocol to engineer time-dependent Hamiltonians inversely for geometric quantum computation. By utilizing SU(2) transformation, a speedup goal on gate operation is achieved with more freedom to design the control parameters. As an application, this protocol enables the conventional and unconventional nonadiabatic geometric quantum gates with desired evolution paths by controlling the microwave pulses in the diamond nitrogen-vacancy center system. We show that the inversely designed Hamiltonian can fulfill the geometric gate with more economical evolution time and further reduces the influence of the environment noise on gate fidelity.

quant-ph↗

arXiv2020

Lie transformation on shortcut to adiabaticity in parametric driving quantum system

Shortcut to adiabaticity (STA) is a speed way to produce the same final state that would result in an adiabatic, infinitely slow process. Two typical techniques to engineer STA are developed by either introducing auxiliary counterdiabatic fields or finding new Hamiltonians that own dynamical invariants to constraint the system into the adiabatic paths. In this paper, a consistent method is introduced to naturally connect the above two techniques with a unified Lie algebraic framework, which neatly removes the requirements of finding instantaneous states in the transitionless driving method and the invariant quantities in the invariant-based inverse engineering approach. The general STA schemes for different potential expansions are concisely achieved with the aid of this method.

quant-ph↗