Dynamics of ‘quantumness’ measures in the decohering harmonic oscillator

Pramana

ADAM T C STEEGE²  ARJENDU K PATTANAYAK1²  TYLER E KEATING²  PETER A ROSE²  ANDREW C McCLUNG²  ERIC S EGGE¹ 

[1] Department of Mathematics, Carleton College, One North College Street, Northfield, MN 55057, USA$$;Department of Physics and Astronomy, Carleton College, One North College Street, Northfield, MN 55057, USA$$

关键词: Decoherence;    non-classicality;    quantum harmonic oscillator;   

DOI  :  

学科分类：物理（综合）

来源: Indian Academy of Sciences

【 摘 要 】

We studied the behaviour under decoherence of four different measures of the distance between quantum states and classical states for the harmonic oscillator coupled to a linear Markovian bath. Three of these are relative measures, using different definitions of the distance between the given quantum states and the set of all classical states. The fourth measure is an absolute one, the negative volume of the Wigner function of the state. All four measures are found to agree, in general, with each other. When applied to the eigenstates $|n rangle$, all four measures behave non-trivially as a function of time during dynamical decoherence. First, we find that the first set of classical states to which the set of eigenstate evolves is (by all measures used) closest to the initial set. That is, all the states decohere to classicality along the ‘shortest path’. Finding this closest classical set of states helps improve the behaviour of all the relative distance measures. Second, at each point in time before becoming classical, all measures have a state $n*$ with maximal quantum-classical distance; the value $n*$ decreases as a function of time. Finally, we explore the dynamics of these non-classicality measures for more general states.

【 授权许可】

Unknown