USA - bilateral cooperation in dynamics and noise in nanodevices

We propose collaborative effort in studies of quantum dynamics and noise in novel devices for nanoelectronics, with focus on building blocks for future quantum computers ? quantum bits (qubits) and logical gates. The main obstacle in realizing quantum alg orithms is random time-dependent fields (noise) generated by the device environment. We will develop a theory of environment-induced decoherence for qubits and logical gates using the concept of disorder-induced dynamic defects (fluctuators) in the enviro nment that produce noise. It will explain recent experimental findings in prototype devices and allow optimizing their performance. We will also address bolometric sensors and detectors of electromagnetic radiation using hopping insulator as a working m edium. They are extensively used because of very large dark resistance. Our new theory of the low-frequency noise limiting sensitivity of such devices will be based on the concept of rare defect clusters with correlated occupation of the sites. This conce pt recently allowed us to explain experimentally observed decreasing temperature dependence of the noise in Si bolometers. We will generalize it and develop quantitative analytical theory and numerical models of the noise, as well as of dielectric relaxat ion and memory effects in such systems.