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Published byWilfred Campbell Modified over 9 years ago
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Review of lecture 5 and 6 Quantum phase space distributions: Wigner distribution and Hussimi distribution. Eigenvalue statistics: Poisson and Wigner level spacing distribution functions; random matrix theory.
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Quantum phenomena
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So why is there any chaos at all, classical or quantum? Answer: Classical mechanics is singular limit of quantum limits.
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Ehrenfest criteria And why it breaks down for quantum chaotic systems…
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Ehrenfest criteria
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Exponentially diverging trajectories changes this sitiuation: for conserving systems then some trajectories must be exponetially converging.
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Quantum distribution functions: General theory
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Wigner distribution This function is not always positive!
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Hussimi distribution
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Example: Harmonic oscillator Wave packet centre never follows classical motion: coherent state needed to describe this. Or….
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Example: Kicked rotator Remarkable resemblance of quantum “phase space” representation of eigenstate with classical picture.
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Example: Kicked rotator
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Eigenvalue statistics Poisson Wigner
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Integrable systems
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Uncorrelated eigenvalues
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Non-integrable systems Replace these blocks by random matrices
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Non-integrable systems Symmetry requirements for random matrix blocks
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Gaussian ensembles
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Thus two classes of random matrix ensembles: Gaussian Orthogonal Ensemble Gaussian Unitary Ensemble and a third (for case of time reversal + spin ½): Gaussian Sympleptic Ensemble
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Eigenvalue correlations
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All these systems show same GOE behavior! Sinai billiard Hydrogen atom in strong magnetic field NO 2 molecule Acoustic resonance in quartz block Three dimension chaotic cavity Quarter-stadium shaped plate Can you match each system to one of the plots on the right…?
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Eigenvalue correlations
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