Saeki, Mizuhiko, Uchiyama, Chikako, Mori, Takashi, Miyashita, Seiji
Relation among various expressions of the complex admittance for quantum systems in contact with heat reservoir is studied. Exact expressions of the complex admittance are derived in various types of...
Master equation approach to line shape in dissipative systems (2009)
Uchiyama, Chikako, Aihara, Masaki, Saeki, Mizuhiko, Miyashita, Seiji
We propose a formulation to obtain the line shape of a magnetic response with dissipative effects that directly reflects the nature of the environment. Making use of the fact that the time evolution...
Generation and Suppression of Decoherence in Artificial Environment for Qubit System (2006)
Kondo, Yasushi, Nakahara, Mikio, Tanimura, Shogo, Kitajima, Sachiko, Uchiyama, Chikako, Shibata, Fumiaki
It is known that a quantum system with finite degrees of freedom can simulate a composite of a system and an environment if the state of the hypothetical environment is randomized by external...
Multi pulse control of entanglement (2004)
Uchiyama, Chikako, Aihara, Masaki
We study the effectiveness of multi pulse control to suppress the degradation of entanglement. Based on a linearly interacting spin-boson model, we show that the multi pulse application recovers the...
Control of entanglement with multipulse application (2004)
Uchiyama, Chikako, Aihara, Masaki
We show that the multipulse application can suppress the degradation of the quantum entanglement with focusing on the concurrence, the degree of entanglement. By evaluating the time evolution of...
Synchronized pulse control of decoherence (2003)
Uchiyama, Chikako, Aihara, Masaki
We present a new strategy for multipulse control over decoherence. When a two-level system interacts with a reservoir characterized by a specific frequency, we find that the decoherence is...
Multipulse Control of Decoherence (2002)
Uchiyama, Chikako, Aihara, Masaki
We present a general formulation to suppress pure dephasing by multipulse control. The formula is free from a specific form of interaction and is expressed in terms of the correlation function of...