An improvement of Schrödinger's uncertainty relation

Nathan Steiger, Jean-François S. Van Huele

Qiu-Cheng Song, Cong‐Feng Qiao

Shunlong Luo, Zhengmin Zhang

Zhongsheng Pu, Kangkang Fan, Guanqiang Song +1 more

Compared with the Heisenberg uncertainty relation, Schrodinger-Robertson uncertain relation generally provides stronger bound on product of uncertainties for two noncommutation observables, so the stricter separability condition can be provided by using Schrodinger-Robertson uncertainty relation. In this paper, using the Schrodinger Robertson uncertainty relation, the separability condition previously proposed by L. M. Duan is improved into the stricter separability condition. Then we extend the above ideas to the general two-mode situation and multi-mode terms, some new separation conditions are obtained.

Shigeru Furuichi

We shall give an alternative Schr\"odinger-type uncertainty relation for a quantity representing a quantum uncertainty, introduced by Luo [Phys. Rev. A 72, 042110 (2005)]. Our result improves the Heisenberg-type uncertainty relation shown in Luo's paper for a mixed state.

Yong‐Moon Park

We study a possible improvement of uncertainty relations. The Heisenberg uncertainty relation employs commutator of a pair of conjugate observables to set the limit of quantum measurement of the observables. The Schrödinger uncertainty relation improves the Heisenberg uncertainty relation by adding the correlation in terms of anti-commutator. However both relations are insensitive whether the state used is pure or mixed. We improve the uncertainty relations by introducing additional terms which measure the mixtureness of the state. For the momentum and position operators as conjugate observables and for the thermal state of quantum harmonic oscillator, it turns out that the equalities in the improved uncertainty relations hold.