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We demonstrate single-electron pumping in a gate-defined carbon nanotube double quantum dot. By periodic modulation of the potentials of the two quantum dots, we move the system around charge triple points and transport exactly one electron or hole per cycle. We investigate the pumping as a function of the modulation frequency and amplitude and observe good current quantization up to frequencies of 18 MHz where rectification effects cause the mechanism to break down. [ABSTRACT FROM AUTHOR]

The authors demonstrate the feasibility of ballistic electron spectroscopy as a tool for mesoscopic physics. A quantum dot is utilized as an energy-selective detector of nonequilibrium ballistic electrons injected into a two-dimensional electron system. In this letter they use a second quantum dot as the electron injector to evaluate the scheme. They propose an application in the study of interacting one- and zero-dimensional systems. [ABSTRACT FROM AUTHOR]

A sapphire cell was used to obtain a high 3He nuclear polarization by means of spin-exchange optical pumping. The phase-shift difference between ordinary and extraordinary rays is well controlled using the thickness of the birefringent sapphire window so that a high circular polarization is obtained in the cell. Neutron transmission through the polarized 3He gas was measured as a function of neutron energy. A large 3He polarization of 63±1% was obtained at a 3He pressure of 3.1 atm. Neutron polarizations of 97 and 90 % were obtained with transmission rates of 15 and 22 % at 10 and 20 meV, respectively. [ABSTRACT FROM AUTHOR]

We present a thermometry scheme to extract the temperature of a two-dimensional electron gas by monitoring the charge occupation of a weakly tunnel-coupled 'thermometer' quantum dot using a quantum point contact detector. Electronic temperatures between 120 and 951 mK are measured with an accuracy of better than 1 mK in the best case, and agree with the lattice temperature measured by a resistance thermometer. The thermometer is non-invasive and does not pass a current through the electron system being measured. The tuning is independent of temperature, and the device is robust in a magnetic field up to 5.6 T. [ABSTRACT FROM AUTHOR]