Non-equilibrium Fluctuation Relations in a Quantum Coherent Conductor (2009)
Nakamura, Shuji, Yamauchi, Yoshiaki, Hashisaka, Masayuki, Chida, Kensaku, Kobayashi, Kensuke, Ono, Teruo, ...
We experimentally demonstrate the validity of non-equilibrium fluctuation relations by using a quantum coherent conductor. In equilibrium the fluctuation-dissipation relation leads to the correlation...
Heat conduction in a three dimensional anharmonic crystal (2009)
We perform nonequilibrium simulations of heat conduction in a three dimensional anharmonic lattice. By studying slabs of length N and width W, we examine the cross-over from one-dimensional to three...
Semiclassical Theory for Universality in Quantum Chaos with Symmetry Crossover (2009)
Saito, Keiji, Nagao, Taro, Muller, Sebastian, Braun, Petr
We address the quantum-classical correspondence for chaotic systems with a crossover between symmetry classes. We consider the energy level statistics of a classically chaotic system in a weak...
Cooling mechanisms in molecular conduction junctions (2009)
Galperin, Michael, Saito, Keiji, Balatsky, Alexander V., Nitzan, Abraham
While heating of a current carrying Ohmic conductors is an obvious consequence of the diffusive nature of the conduction in such systems, current induced cooling has been recently reported in some...
Nonlinear Kelvin-Onsager Relations for Thermoelectric Quantum Transport (2009)
Iyoda, Eiki, Utsumi, Yasuhiro, Kato, Takeo, Saito, Keiji
We discuss a consequence of time reversal symmetry on thermoelectric effect in nonequilibrium coherent quantum transport. Starting with a quantum version of the fluctuation theorem, we show that...
Fluctuation Theorem in a Quantum-Dot Aharonov-Bohm Interferometer (2008)
Utsumi, Yasuhiro, Saito, Keiji
In the present study, we investigate the full counting statistics in a two-terminal Aharonov-Bohm interferometer embedded with an interacting quantum dot. We introduce a novel saddle-point solution...
Energy Dissipation and Fluctuation-Response in Driven Quantum Langevin Dynamics (2008)
Energy dissipation in a nonequilibrium steady state is studied in driven quantum Langevin systems. We study energy dissipation flow to thermal environment, and obtain a general formula for the...
Saito, Keiji, Utsumi, Yasuhiro
We study full counting statistics of coherent electron transport through multi-terminal interacting quantum-dots under a finite magnetic field. Microscopic reversibility leads to the symmetry of the...
Coherent destruction of tunneling, dynamic localization and the Landau-Zener formula (2007)
Kayanuma, Yosuke, Saito, Keiji
We clarify the internal relationship between the coherent destruction of tunneling (CDT) for a two-state model and the dynamic localization (DL) for a one-dimensional tight-binding model, under the...
Fluctuation theorem in quantum heat conduction (2007)
We consider steady state heat conduction across a quantum harmonic chain connected to reservoirs modelled by infinite collection of oscillators. The heat, $Q$, flowing across the oscillator in a time...
Dissipative Landau-Zener transitions of a qubit: bath-specific and universal behavior (2007)
Saito, Keiji, Wubs, Martijn, Kohler, Sigmund, Kayanuma, Yosuke, Hanggi, Peter
We study Landau-Zener transitions in a qubit coupled to a bath at zero temperature. A general formula is derived that is applicable to models with a non-degenerate ground state. We calculate exact...
Gauging a quantum heat bath with dissipative Landau-Zener transitions (2006)
Wubs, Martijn, Saito, Keiji, Kohler, Sigmund, Hänggi, Peter, Kayanuma, Yosuke
We calculate the exact Landau-Zener transitions probabilities for a qubit with arbitrary linear coupling to a bath at zero temperature. The final quantum state exhibits a peculiar entanglement...
Quantum state preparation in circuit QED via Landau-Zener tunneling (2006)
Saito, Keiji, Wubs, Martijn, Kohler, Sigmund, Hanggi, Peter, Kayanuma, Yosuke
We study a qubit undergoing Landau-Zener transitions enabled by the coupling to a circuit-QED mode. Summing an infinite-order perturbation series, we determine the exact nonadiabatic transition...
Landau-Zener transitions in qubits controlled by electromagnetic fields (2005)
Wubs, Martijn, Saito, Keiji, Kohler, Sigmund, Kayanuma, Yosuke, Hanggi, Peter
We investigate the influence of a dipole interaction with a classical radiation field on a qubit during a continuous change of a control parameter. In particular, we explore the non-adiabatic...
Martijn Wubs, Keiji Saito, Sigmund Kohler, Yosuke Kayanuma, Peter Hänggi
open–access journal for physics Landau–Zener transitions in qubits controlled by electromagnetic fields
Nonadiabatic Electron Manipulation in Quantum-Dot Arrays (2004)
Saito, Keiji, Kayanuma, Yosuke
A novel method of coherent manipulation of the electron tunneling in quantum-dots is proposed, which utilizes the quantum interference in nonadiabatic double-crossing of the discrete energy levels....
Wave Packet Propagation and Electric Conductivity of Nanowires (2003)
Maeda, Munehiko, Saito, Keiji, Miyashita, Seiji, De Raedt, Hans
We compute the electric conductivity of nanowires in the presence of magnetic domain walls by the method of wave packet propagation. We demonstrate that the propagation through the wire depends on...
Transport anomaly in the low energy regime of spin chains (2002)
The anomalous thermal conductivity in spin chains observed in experiments is studied for the low temperature regime. In the effective dynamics with most realistic perturbations, the so-called Umklapp...
Nishino, Masamichi, Saito, Keiji, Miyashita, Seiji
We study effect of noise on the tunneling process of the magnetization in a sweeping field from the viewpoint of the nonadiabatic transition. The tunneling probability depends on the properties of...