Adiabatic quantum computation along quasienergies (2009)
The parametric deformations of quasienergies and eigenvectors of unitary operators are applied to the design of quantum adiabatic algorithms. The conventional, standard adiabatic quantum computation...
Recovery of chaotic tunneling due to destruction of dynamical localization by external noise (2009)
Ishikawa, Akiyuki, Tanaka, Atushi, Shudo, Akira
Quantum tunneling in the presence of chaos is analyzed, focusing especially on the interplay between quantum tunneling and dynamical localization. We observed flooding of potentially existing...
Exotic quantum holonomy in Hamiltonian systems (2009)
Cheon, Taksu, Tanaka, Atushi, Kim, Sang Wook
We study the evolution of quantum eigenstates in the presence of level crossing under adiabatic cyclic change of environmental parameters. We find that exotic holonomies, indicated by exchange of the...
Exotic quantum holonomy induced by degeneracy hidden in complex parameter space (2009)
Kim, Sang Wook, Cheon, Taksu, Tanaka, Atushi
An adiabatic change of a bound state along a closed circuit in the parameter space can induces holonomies not only in the phase of the state, but also in the associated eigenspace and eigenvalue. The...
A Unified Theory of Quantum Holonomies (2009)
A periodic change of slow environmental parameters of a quantum system induces quantum holonomy. The phase holonomy is a well-known example. Another is a more exotic kind that exhibits eigenvalue and...
New anatomy of quantum holonomy (2008)
We present a unified formulation of quantum holonomy which is capable of describing all of its known varieties. The full role of non-Abelian gauge connection is elucidated. As examples, solvable...
Cheon's anholonomies in Floquet operators (2007)
Miyamoto, Manabu, Tanaka, Atushi
Anholonomies in the parametric dependences of the eigenvalues and the eigenvectors of Floquet operators that describe unit time evolutions of periodically driven systems, e.g., kicked rotors, are...
Quantum suppression of chaotic tunneling (2007)
Ishikawa, Akiyuki, Tanaka, Atushi, Shudo, Akira
The interplay between chaotic tunneling and dynamical localization in mixed phase space is investigated. Semiclassical analysis using complex classical orbits reveals that tunneling through torus...
Quasienergy anholonomy and its application to adiabatic quantum state manipulation (2007)
Tanaka, Atushi, Miyamoto, Manabu
The parametric dependence of a quantum map under the influence of a rank-1 perturbation is investigated. While the Floquet operator of the map and its spectrum have a common period with respect to...
The evaluation of a tunneling tail by the Herman-Kluk method, which is a quasiclassical way to compute quantum dynamics, is examined by asymptotic analysis. In the shallower part of the tail, as well...
Dynamical aspects of quantum entanglement for coupled mapping systems (2003)
Fujisaki, Hiroshi, Tanaka, Atushi, Miyadera, Takayuki
We investigate how the dynamical production of quantum entanglement for weakly coupled mapping systems is influenced by the chaotic dynamics of the corresponding classical system. We derive a general...
Dynamical aspects of quantum entanglement for weakly coupled kicked tops (2002)
Fujisaki, Hiroshi, Miyadera, Takayuki, Tanaka, Atushi
We investigate how the dynamical production of quantum entanglement for weakly coupled, composite quantum systems is influenced by the chaotic dynamics of the corresponding classical system, using...
Tanaka, Atushi, Fujisaki, Hiroshi, Miyadera, Takayuki
The production of quantum entanglement between weakly coupled mapping systems, whose classical counterparts are both strongly chaotic, is investigated. In the weak coupling regime, it is shown that...
Semiclassical theory of weak values (2002)
Aharonov-Albert-Vaidman's weak values are investigated by a semiclassical method. Examples of the semiclassical calculation that reproduces "anomalous" weak values are shown. Furthermore, a complex...
Phase space caustics in multi-component systems (1998)
As examples of quantum-"classical" coupling systems, multi-component systems are studied by semiclassical evaluations of the Feynman kernels in the coherent-state representation. From the observation...