Coherent-Squeezed State Representation of Travelling General Gaussian Wave Packets
Coherent-Squeezed State Representation of Travelling General Gaussian Wave Packets
复制标题
行进的一般高斯波包的相干压缩状态表示
DOI:
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发表时间:
2005
期刊:
影响因子:
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通讯作者:
Sang Pyo Kim
中科院分区:
文献类型:
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作者:
Sang Pyo Kim
Using the time-dependent annihilation and creation operators, the invariant operators, for a free mass and an oscillator, we find the coherent-squeezed state representation of a travelling general Gaussian wave packet with initial expectation values, $x_0$ and $p_0$, of the position and momentum and variances, $Delta x_0$ and $Delta p_0$. The initial general Gaussian wave packet takes, up to a normalization factor, the form $e^{i p_0 x/hbar} e^{- (1 mp i delta) (x - x_0)^2 / 4 (Delta x_0)^2}$, where $delta = sqrt{(2Delta x_0 Delta p_0/hbar)^2 -1}$ denotes a measure of deviation from the minimum uncertainty or the initial position-momentum correlation $delta = 2Delta (xp)_0 / hbar$. The travelling Gaussian wave packet takes, up to a time-dependent phase and normalization factor, the form $e^{i p_c x/hbar} e^{- (1 - 2 i Delta (xp)_t/hbar) (x - x_c)^2 / 4 (Delta x_t)^2}$ and the centroid follows the the classical trajectory with $x_c(t)$ and $p_c(t)$. The position variance is found to have additionally a linearly time-dependent term proportional to $delta$ with both positive and negative signs.