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We develop an analytical approach to the spectral form factor and out-of-time ordered correlators in zero-dimensional Brownian models of quantum chaos. The approach expresses these spectral correlations as part of a closed hierarchy of…

Mesoscale and Nanoscale Physics · Physics 2025-04-02 Tara Kalsi , Alessandro Romito , Henning Schomerus

We prove spatial decay estimates on disorder-averaged position-momentum correlations in a gapless class of random oscillator models. First, we prove a decay estimate on dynamic correlations for general eigenstates with a bound that depends…

Mathematical Physics · Physics 2018-02-23 Houssam Abdul-Rahman , Robert Sims , Günter Stolz

The distortion of the regular motion in a quantum system by its coupling to the continuum of decay channels is investigated. The regular motion is described by means of a Poissonian ensemble. We focus on the case of only few channels K<10.…

chao-dyn · Physics 2009-10-30 T. Gorin , F. --M. Dittes , M. Müller , I. Rotter , T. H. Seligman

In previous work, we associated to any finite simple graph a particular set of derangements of its vertices. These derangements are in bijection with the spheres in the wedge sum describing the homotopy type of the boolean complex for this…

Combinatorics · Mathematics 2011-04-06 Kari Ragnarsson , Bridget Eileen Tenner

We present experimental results on the eigenfrequency statistics of a superconducting, chaotic microwave billiard containing a rotatable obstacle. Deviations of the spectral fluctuations from predictions based on Gaussian orthogonal…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 B. Dietz , A. Heine , A. Richter , O. Bohigas , P. Leboeuf

A crucial result in quantum chaos, which has been established for a long time, is that the spectral properties of classically integrable systems generically are described by Poisson statistics whereas those of time-reversal symmetric,…

Quantum Physics · Physics 2017-01-04 Pei Yu , Zi-Yuan Li , Hong-Ya Xu , Liang Huang , Barbara Dietz , Celso Grebogi , Ying-Cheng Lai

The standard Bloch oscillation normally refers to the oscillatory tunneling dynamics of quantum particles in a periodic lattice plus a linear gradient. In this work we theoretically investigate the generalized form of the Bloch oscillation…

Atomic Physics · Physics 2019-11-13 Qian-Ru Zhu , Shou-Long Chen , Shao-Jun Li , Xue-Ting Fang , Lushuai Cao , Zhong-Kun Hu

We consider a modification of the Berry Conjecture for eigenmode statistics in wave-bearing systems. The eigenmode correlator is conjectured to be proportional to the imaginary part of the Green's function. The generalization is applicable…

Disordered Systems and Neural Networks · Physics 2009-11-10 Alexei Akolzin , Richard L. Weaver

Driven-dissipative condensates, such as those formed from polaritons, expose how the coherence of Bose-Einstein condensates evolves far from equilibrium. We consider the phase and frequency ordering in the steady-states of a one-dimensional…

Mesoscale and Nanoscale Physics · Physics 2023-11-10 John P. Moroney , Paul R. Eastham

Spectral singularities that spoil the completeness of Bloch-Floquet states may occur in non-Hermitian Hamiltonians with complex periodic potentials. Here an equivalence is established between spectral singularities in complex crystals and…

Quantum Physics · Physics 2015-05-14 S. Longhi

A microscopic statistical model of a quantum solid is developed, where inside a crystalline lattice there can exist regions of disorder, such as dislocation networks or grain boundaries. The cores of these regions of disorder are allowed…

Statistical Mechanics · Physics 2023-01-04 V. I. Yukalov , E. P. Yukalova

The impact of disorder in the vibrational bath of an ensemble of open quantum systems is explored, arising either from variation in the overall coupling strength or from uncertainty in the shape of the environment spectral function. Such…

Quantum Physics · Physics 2015-05-21 Samuel L. Smith , Alex W. Chin

Quantum chaotic dynamics is obtained for a tight-binding model in which the energies of the atomic levels at the boundary sites are chosen at random. Results for the square lattice indicate that the energy spectrum shows a complex behavior…

chao-dyn · Physics 2009-10-28 E. Cuevas , E. Louis , J. A. Verges

In the recent years, much attention has been devoted to the inhomogeneous nature of the mechanical response at the nano-scale in disordered solids. Clearly, the elastic heterogeneities that have been characterized in this context are…

Disordered Systems and Neural Networks · Physics 2014-08-26 Hideyuki Mizuno , Stefano Mossa , Jean-Louis Barrat

Contrary to prevailing notion we find that the spectrum associated with the extended states in a complex system may belong to the Poisson universality class if the system is subjected to a specific set of constraints. Our results are based…

Statistical Mechanics · Physics 2017-06-07 Triparna Mondal , Suchetana Sadhukhan , Pragya Shukla

Complex bands $\vec{k}^{\perp}(E)$ in a semiconductor crystal, along a general direction $\vec{n}$, can be computed by casting Schr\"odinger's equation as a generalized polynomial eigenvalue problem. When working with primitive lattice…

Mesoscale and Nanoscale Physics · Physics 2014-07-24 Arvind Ajoy , Kota V R M Murali , Shreepad Karmalkar

We show that a {\em vibrational instability} of the spectrum of weakly interacting quasi-local harmonic modes creates the maximum in the inelastic scattering intensity in glasses, the Boson peak. The instability, limited by anharmonicity,…

Disordered Systems and Neural Networks · Physics 2009-11-07 V. L. Gurevich , D. A. Parshin , H. R. Schober

We investigate the vibrational properties of topologically disordered materials by analytically studying particles that harmonically oscillate around random positions. Exploiting classical field theory in the thermodynamic limit at $T=0$,…

Disordered Systems and Neural Networks · Physics 2023-06-09 Florian Vogel , Matthias Fuchs

Orthogonal - unitary and symplectic - unitary crossover ensembles of random matrices are relevant in many contexts, especially in the study of time reversal symmetry breaking in quantum chaotic systems. Using skew-orthogonal polynomials we…

Mathematical Physics · Physics 2011-05-30 Santosh Kumar , Akhilesh Pandey

We consider a system of coupled classical harmonic oscillators with spatially fluctuating nearest-neighbor force constants on a simple cubic lattice. The model is solved both by numerically diagonalizing the Hamiltonian and by applying the…

Condensed Matter · Physics 2009-10-31 W. Schirmacher , G Diezemann , C. Ganter