Related papers: Precision measurement of an electron pump at 2 GHz
Femtosecond optical pump-probe technique is used to study charge carrier dynamics in few-layer MoS2 samples fabricated by mechanical exfoliation. An ultrafast pump pulse excites carriers and differential reflection of a probe pulse tuned to…
This paper reports a newly developed high current transformer-rectifier High-Tc Superconducting (HTS) flux pump switched by dynamic resistance. A quasi-persistent current of over 1.1 kA has been achieved at 77 K using the device, which is…
In this paper we present a technique for the precise measurement of electric dipole allowed transitions in trapped ions. By applying a probe and a cooling laser in quick succession, the full transition can be probed without causing…
We report on two-terminal-pair and four-terminal-pair test measurements of a 10-kohm resistance standard by means of a commercial precision LCR meter at frequencies up to 2 MHz. In the case of a two-terminal-pair configuration, we…
Measurements with a one-electron quantum cyclotron determine the electron magnetic moment, given by $g/2 = 1.001\,159\,652\,180\,73\,(28)\,[0.28~\textrm{ppt}]$, and the fine structure constant,…
In the optical pumping systems based on the pump-probe arrangement, the spin polarization of the atoms is generally monitored utilizing the probe laser beam, in which way an extra perturbation must be introduced and thus affects the normal…
A programmable quantum current generator based on the application of Ohm's law to quantum voltage and resistance standards has demonstrated a realization of the ampere from the elementary charge with a $10^{-8}$ relative uncertainty [J.…
A 128-channel picoammeter system is constructed based on instrumentation amplifiers. Taking the advantages of high electric potential and narrow bandwidth in DC energetic charged beam measurements, current resolution better than 5 fA can be…
Pure spin currents are shown to be generated by an electrically controlled quantum pump applied at the edges of a topological insulator. The electric rather than the more conventional magnetic control offers several advantages and avoids,…
A measurement using a one-electron quantum cyclotron gives the electron magnetic moment in Bohr magnetons, g/2 = 1.001 159 652 180 73 (28) [0.28 ppt], with an uncertainty 2.7 and 15 times smaller than for previous measurements in 2006 and…
This paper describes the design of a low-cost USB-controlled potentiostat/galvanostat which can measure or apply potentials in the range of +/-8V, and measure or apply currents ranging from nanoamps to max. +/-25 mA. Precision is excellent…
We present transport measurements of electrons on the surface of liquid helium in a microchannel device in which a constriction may be formed by a split-gate electrode. The surface electron current passing through the microchannel first…
We demonstrate an ultrafast voltage sampling technique using a stream of electron wavepackets. Electrons are emitted from a single-electron pump and travel through electron waveguides towards a detector potential barrier. Our electrons…
This note describes the design and testing of a programmable pulsatile flow pump using an Arduino micro-controller. The goal of this work is to build a compact and affordable system that can relatively easily be programmed to generate…
We present femtosecond transient transmission (or absorbance) measurements in silicon nanowires in the energy range 1.1-3.5 eV, from below the indirect band-gap to above the direct band-gap. Our pump-probe measurements allow us to give a…
Here we perform a series of time-resolved experiments where a 100 fs pump pulse is tuned between 528 nm and 555 nm, across the second indirect gap of intrinsic silicon at ~540 nm which involves electrons in a higher-lying conduction band…
A new type of gaseous micropattern particle detector based on a closed-cell microcavity plasma panel sensor is reported. The first device was fabricated with 1 x 1 x 2 mm cells. It has shown very clean signals of 0.6 to 2.5 volt amplitude,…
In 2003 we have measured the absolute frequency of the $(1S, F=1, m_F=\pm 1) \leftrightarrow (2S, F'=1, m_F'=\pm 1)$ two-photon transition in atomic hydrogen. We observed a variation of $(-29\pm 57)$ Hz over a 44 months interval separating…
We reported a systematic study of spin-orbit torque biased magnetic sensors based on NiFe/Pt bilayers through both macro-spin modeling and experiments. The simulation results show that it is possible to achieve a linear sensor with a…
Recently it has been shown that ac-driven double quantum dots can act as spin pumps and spin filters. By calculating the current through the system for each spin polarization, by means of the time evolution of the reduced density matrix in…