1,117 research outputs found
Level velocity statistics of hyperbolic chaos
A generalized version of standard map is quantized as a model of quantum
chaos. It is shown that, in hyperbolic chaotic regime, second moment of quantum
level velocity is as predicted by the random matrix theory.Comment: 11 pages, 4 figure
Transport of Entanglement Through a Heisenberg-XY Spin Chain
The entanglement dynamics of spin chains is investigated using Heisenberg-XY
spin Hamiltonian dynamics. The various measures of two-qubit entanglement are
calculated analytically in the time-evolved state starting from initial states
with no entanglement and exactly one pair of maximally-entangled qubits. The
localizable entanglement between a pair of qubits at the end of chain captures
the essential features of entanglement transport across the chain, and it
displays the difference between an initial state with no entanglement and an
initial state with one pair of maximally-entangled qubits.Comment: 5 Pages. 3 Figure
Quenching and generation of random states in a kicked Ising model
The kicked Ising model with both a pulsed transverse and a continuous
longitudinal field is studied numerically. Starting from a large transverse
field and a state that is nearly an eigenstate, the pulsed transverse field is
quenched with a simultaneous enhancement of the longitudinal field. The
generation of multipartite entanglement is observed along with a phenomenon
akin to quantum resonance when the entanglement does not evolve for certain
values of the pulse duration. Away from the resonance, the longitudinal field
can drive the entanglement to near maximum values that is shown to agree well
with those of random states. Further evidence is presented that the time
evolved states obtained do have some statistical properties of such random
states. For contrast the case when the fields have a steady value is also
discussed.Comment: 7 pages, 7 figure
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