Publications

Results 26–50 of 59

Search results

Jump to search filters

Single shot spin readout using a cryogenic high-electron-mobility transistor amplifier at sub-Kelvin temperatures

Applied Physics Letters

Tracy, Lisa A.; Luhman, Dwight R.; Carr, Stephen M.; Bishop, N.C.; Ten Eyck, Gregory A.; Pluym, Tammy P.; Wendt, J.R.; Lilly, Michael L.; Carroll, Malcolm

We use a cryogenic high-electron-mobility transistor circuit to amplify the current from a single electron transistor, allowing for demonstration of single shot readout of an electron spin on a single P donor in Si with 100 kHz bandwidth and a signal to noise ratio of ∼9. In order to reduce the impact of cable capacitance, the amplifier is located adjacent to the Si sample, at the mixing chamber stage of a dilution refrigerator. For a current gain of ∼ 2.7 × 10 3, the power dissipation of the amplifier is 13 μW, the bandwidth is ∼ 1.3 MHz, and for frequencies above 300 kHz the current noise referred to input is ≤ 70 fA/ Hz. With this amplification scheme, we are able to observe coherent oscillations of a P donor electron spin in isotopically enriched 28Si with 96% visibility.

More Details
TYPE Journal Article YEAR 2016
DOIOSTIScopus

Cryogenic Preamplification of a Single-Electron-Transistor using a Silicon-Germanium Heterojunction-Bipolar-Transistor

Applied Physics Letters

Curry, Matthew J.; England, Troy D.; Bishop, Nathaniel; Ten Eyck, Gregory A.; Wendt, J.R.; Pluym, Tammy P.; Lilly, Michael L.; Carr, Stephen M.; Carroll, Malcolm

We examine a silicon-germanium heterojunction bipolar transistor (HBT) for cryogenic pre-amplification of a single electron transistor (SET). The SET current modulates the base current of the HBT directly. The HBT-SET circuit is immersed in liquid helium, and its frequency response from low frequency to several MHz is measured. The current gain and the noise spectrum with the HBT result in a signal-to-noise-ratio (SNR) that is a factor of 10–100 larger than without the HBT at lower frequencies. Furthermore, the transition frequency defined by SNR = 1 has been extended by as much as a factor of 10 compared to without the HBT amplification. The power dissipated by the HBT cryogenic pre-amplifier is approximately 5 nW to 5 μW for the investigated range of operation. We found that the circuit is also operated in a single electron charge read-out configuration in the time-domain as a proof-of-principle demonstration of the amplification approach for single spin read-out.

More Details
TYPE Journal Article YEAR 2015
DOIOSTI
Results 26–50 of 59
Results 26–50 of 59