2017/09/30 by Francesco Campaioli, Felix A. Pollock, Felix C. Binder +1 · 2 citations
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.120.060409
published as Phys. Rev. Lett. 120, 060409 (2018) · Updated and revised version; 5 pages, 2 figures, 1 page appendix
arxiv created 2017/10/10 · arxiv updated 2018/02/14
Conventional quantum speed limits perform poorly for mixed quantum states: They are generally not tight and often significantly underestimate the fastest possible evolution speed. To remedy this, for unitary driving, we derive two quantum speed limits that outperform the traditional bounds for almost all quantum states. Moreover, our bounds are significantly simpler to compute as well as experimentally more accessible. Our bounds have a clear geometric interpretation; they arise from the evaluation of the angle between generalized Bloch vectors.