arXiv subjects

C. C. Chong

Publications and source records attributed to C. C. Chong.

6 recordsLinked to original sources

arXiv2005

Electron interference in mesoscopic devices in the presence of nonclassical electromagnetic fields

The interaction of mesoscopic interference devices with nonclassical electromagnetic fields is studied. The external quantum fields induce a phase factor on the electric charges. This phase factor, which is a generalization of the standard Aharonov-Bohm phase factor, is in the case of nonclassical electromagnetic fields a quantum mechanical operator. Its expectation value depends on the density matrix describing the nonclassical photons and determines the interference. Several examples are discussed, which show that the quantum noise of the nonclassical photons destroys slightly the electron interference fringes. An interesting application arises in the context of distant electron interference devices, irradiated with entangled photons. In this case the interfering electrons in the two devices become entangled. The same ideas are applied in the context of SQUID rings irradiated with nonclassical electromagnetic fields. It is shown that the statistics of the Cooper pairs tunneling through the Josephson junction depend on the statistics of the photons.

quant-ph↗

arXiv2004

Entangled quantum currents in distant mesoscopic Josephson junctions

Two mesoscopic SQUID rings which are far from each other, are considered. A source of two-mode nonclassical microwaves irradiates the two rings with correlated photons. The Josephson currents are in this case quantum mechanical operators, and their expectation values with respect to the density matrix of the microwaves, yield the experimentally observed currents. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. Results for two different examples that involve microwaves in number states and coherent states are derived. It is shown that the quantum statistics of the tunnelling electron pairs through the Josephson junctions in the two rings, are correlated.

cond-mat.supr-con↗

arXiv2004

Photon-induced entanglement of distant mesoscopic SQUID rings

An experiment that involves two distant mesoscopic SQUID rings is studied. The superconducting rings are irradiated with correlated photons, which are produced by a single microwave source. Classically correlated (separable) and quantum mechanically correlated (entangled) microwaves are considered, and their effect on the Josephson currents is quantified. It is shown that the currents tunnelling through the Josephson junctions in the distant rings, are correlated.

quant-ph↗

arXiv2004

Entanglement of distant electron interference experiments

Two electron interference experiments which are far from each other are considered. They are irradiated with correlated nonclassical electromagnetic fields, produced by the same source. The phase factors are in this case operators, and their expectation values with respect to the density matrix of the electromagnetic field quantify the observed electron fringes. The correlated photons create correlations between the observed electron intensities. Both cases of classically correlated (separable) and quantum mechanically correlated (entangled) electromagnetic fields are considered. It is shown that the induced correlation between the distant electron interferences is sensitive to the nature of the correlation between the irradiating photons.

quant-ph↗

arXiv2003

Correlations in interfering electrons irradiated by nonclassical microwaves

Electron interference in mesoscopic devices irradiated by external non-classical microwaves, is considered. In the case of one-mode microwaves, it is shown that both the average intensity and the spectral density of the interfering electrons are sensitive to the quantum noise of the microwaves. The results for various quantum states of the microwaves are compared and contrasted with the classical case. Separable and entangled two-mode microwaves are also considered and their effect on electron average intensity and autocorrelation, is discussed.

cond-mat↗

arXiv2002

Correlation properties of interfering electrons in a mesoscopic ring under nonclassical microwave radiation

Interfering electrons in a mesoscopic ring are irradiated with both classical and nonclassical microwaves. The average intensity of the charges is calculated as a function of time and it is found that it depends on the nature of the irradiating electromagnetic field. For various quantum states of the microwaves, the electron autocorrelation function is calculated and it shows that the quantum noise of the external field affects the interference of the charges. Two-mode entangled microwaves are also considered and the results are compared with those of the corresponding separable state. In both cases, the results depend on whether the ratio of the two frequencies is rational or irrational.

cond-mat.mes-hall↗