Projects per year
Abstract
A fundamental problem in quantum engineering is determining the lowest time required to ensure that all possible unitaries can be generated with the tools available, which is one of a number of possible quantum speed limits. We examine this problem from the perspective of quantum control, where the system of interest is described by a drift Hamiltonian and set of control Hamiltonians. Our approach uses a combination of Lie algebra theory, Lie groups, and differential geometry and formulates the problem in terms of geodesics on a differentiable manifold. We provide explicit lower bounds on the quantum speed limit for the case of an arbitrary drift, requiring only that the control Hamiltonians generate a topologically closed subgroup of the full unitary group, and formulate criteria as to when our expression for the speed limit is exact and not merely a lower bound. These analytic results are then tested and confirmed using a numerical optimization scheme. Finally, we extend the analysis to find a lower bound on the quantum speed limit in the common case where the system is described by a drift Hamiltonian and a single control Hamiltonian.
Original language  English 

Article number  052403 
Pages (fromto)  052403105240314 
Number of pages  14 
Journal  Physical Review A: covering atomic, molecular, and optical physics and quantum information 
Volume  108 
Issue number  5 
DOIs  
Publication status  Published  Nov 2023 
Fingerprint
Dive into the research topics of 'Exact and lower bounds for the quantum speed limit in finitedimensional systems'. Together they form a unique fingerprint.Projects
 2 Finished

UTS led: Pushing the digital limits in quantum simulation for advanced manufacturing
Langford, N., Dehollain, J., Burgarth, D., Berry, D. & Heyl, M.
26/03/21 → 25/03/24
Project: Research
