Improved unitary uncertainty relations

Abstract

We derive strong variance-based uncertainty relations for arbitrary two and more unitary operators by re-examining the mathematical foundation of the uncertainty relation. This is achieved by strengthening the celebrated Cauchy-Schwarz inequality using a method of brackets and convex functions. The unitary uncertainty relations outperform several strong unitary uncertainty relations, notably better than some recent best lower bounds such as [Phys. Rev. Lett. 120, 230402 (2018)] and [Phys. Rev. A. 100, 022116 (2019)].

References in corpus (4)

• Conjectured Strong Complementary Information Tradeoff
• Stronger uncertainty relations for the sum of variances
• Simultaneous tracking of spin angle and amplitude beyond classical limits
• An improved bound for strong unitary uncertainty relations with refined sequence