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arXiv quant-ph/0511091quant-ph
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耗散量子动力学中的时间-能量和时间-熵测不准关系

Time-energy and time-entropy uncertainty relations in dissipative quantum dynamics

Gian Paolo Beretta

摘要:

我们推导出精确的关系和一般的不等式,扩展通常的时间-能量不确定性关系从域的酉哈密顿动力学的耗散动力学所描述的广泛的一类线性和非线性演化方程的密度算子。对于非耗散动力学,用Schroedinger不等式代替Heisenberg-Robertson不等式,得到了一个比通常的Mandelstam-Tamm-Messiah关系$τ_FΔ_H\ge \hbar/2$更精确的一般精确的时能测不准关系.对于同时酉/耗散动力学,通常的时间-能量不确定性关系被一个限制性较小的关系所取代,该关系取决于耗散的特征时间$τ$,以及与广义非平衡Massieu函数算子相关的不确定性,该算子定义了假设的一类演化方程的耗散部分的结构。在作者先前介绍的孤立系的最陡熵升耗散量子动力学中,我们得到了有趣的时间-能量和时间-熵不确定关系$(2τ_FΔ_H/ \hbar)^2+ (τ_FΔ_S/k_Bτ)^2 \ge 1$ .我们通过数值模拟说明了这个结果和其他各种不等式。

英文摘要:

We derive exact relations and general inequalities that extend the usual time-energy uncertainty relations from the domain of unitary Hamiltonian dynamics to that of dissipative dynamics as described by a broad class of linear and nonlinear evolution equations for the density operator. For non-dissipative dynamics, by using the Schroedinger inequality instead of the Heisenberg-Robertson inequality, we obtain a general exact time-energy uncertainty relation which is sharper than the usual Mandelstam-Tamm-Messiah relation $τ_FΔ_H\ge \hbar/2$. For simultaneous unitary/dissipative dynamics, the usual time-energy uncertainty relation is replaced by a less restrictive relation that depends on the characteristic time of dissipation, $τ$, and the uncertainty associated with the generalized nonequilibrium Massieu-function operator which defines the structure of the dissipative part of the assumed class of evolution equations. Within the steepest-entropy-ascent dissipative quantum dynamics of an isolated system introduced earlier by this author, we obtain the interesting time-energy and time-entropy uncertainty relation $(2τ_FΔ_H/ \hbar)^2+ (τ_FΔ_S/k_Bτ)^2 \ge 1$. We illustrate this result and various other inequalities by means of numerical simulations.

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