2015/05/31 by Iman Marvian, Daniel A. Lidar · 2 citations
Computer Science · Mathematics · Physics and Astronomy · #Bounded function #Hamiltonian (control theory) #Leakage (economics) #Mathematics #Physics #Quantum #Quantum Computing Algorithms and Architecture #Quantum Information and Cryptography #Quantum decoherence #Quantum mechanics #Quantum system #Spectral gap #Spectroscopy and Quantum Chemical Studies #Statistical physics #Thermal #Thermal equilibrium #Thermal reservoir #cond-mat.stat-mech #quant-ph
paper · pdf · doi:10.1103/physrevlett.115.210402
published as Phys. Rev. Lett. 115, 210402 (2015) · 4 pages+15 pages Supplementary Material, references added, minor edits and clarifications, published version
arxiv created 2015/11/09 · openalex publication_date 2015/11/18 · arxiv updated 2015/11/20 · openalex created_date 2025/10/10 · openalex updated_date 2026/08/06
We introduce state-independent, nonperturbative Hamiltonian quantum speed limits for population leakage and fidelity loss, for a gapped open system interacting with a reservoir. These results hold in the presence of initial correlations between the system and the reservoir, under the sole assumption that their interaction and its commutator with the reservoir Hamiltonian are norm bounded. The reservoir need not be thermal and can be time dependent. We study the significance of energy mismatch between the system and the local degrees of freedom of the reservoir that directly interact with the system. We demonstrate that, in general, by increasing the system gap we may reduce this energy mismatch, and, consequently, drive the system and the reservoir into resonance; this can accelerate fidelity loss, irrespective of the thermal properties or state of the reservoir. This implies that quantum error suppression strategies based on increasing the gap are not uniformly beneficial. Our speed limits also yield an elementary lower bound on the relaxation time of spin systems.