We study the current noise through an unbiased quantum electron pump and its mesoscopic fluctuations for arbitrary temperatures and beyond the bilinear response. In the bilinear regime, we find the full distributions of the noise power and the current-to-noise ratio for chaotic quantum dots with single-channel and many-channel ballistic point contacts. For a dot with many-channel point contacts...

We study an entangled two-mode coherent state within the framework of2×2-dimensional Hilbert space. We investigate the problem of quantum teleportation ofa superposition coherent state via an entangled coherent channel. By three differentmeasures with the titles ``minimum assured fidelity (MASF)”, ``average teleportationfidelity” and ``optimal fidelity (f)” we study the ...

Benchmarking is how the performance of a computing system determined. Surprisingly, even for classical computers this not straightforward process. One must choose appropriate benchmark and metrics to extract meaningful results. Different benchmarks test in different ways, each individual metric may or be interest. Choosing approach tricky. The situation more open ended quantum computers, where ...

Distributed quantum computing can provide substantial noise reduction due to shallower circuits. An experiment illustrates the advantages in case of a Grover search. This motivates study advantage distributed version Simon and Deutsch-Jozsa algorithms. We show that algorithm retains exponential advantage, but complexity deteriorates from $O(n)$ $O({n}^{2})$, where $n={log}_{2}(N)$. The being pr...

A stationary theory of quantum stochastic processes of second order is outlined. It includes KMS processes in wide sense like the equilibrium finite temperature quantum noise given by the Planck’s spectral formula. It is shown that for each stationary noise there exists a natural output process which is identical to the noise in the infinite temperature limit, and flipping with the noise if the...

Title of dissertation: SEARCHING FOR ENTANGLED ELECTRON SPIN STATES WITH SHOT NOISE DETECTION Yuanzhen Chen, Doctor of Philosophy, 2005 Dissertation directed by: Richard A. Webb Department of Physics We report experimental research into the possibility of using shot noise measurements to detect the entangled states of electron spins. The study is part of the effort towards the demonstration of ...

We analyze the problem of directed quantum transport induced by external exponentially correlated telegraphic noise. In addition to quantum nature of the heat bath, nonlinearity of the periodic system potential brings in quantum contribution. We observe that quantization, in general, enhances classical current at low temperature, while the differences become insignificant at higher temperature....

A comprehensive model for the photon number fluctuations and the current noise in quantum cascade lasers is presented. It is shown that the photon intensity noise in quantum cascade lasers exhibits little amplitude squeezing even when noise in the drive current is suppressed below the shot noise value. This is in contrast to interband semiconductor diode lasers in which the laser intensity nois...