The Radio-frequency single electron transistor (rf-SET) is the fastest
and most sensitive electrometer known today. Many schemes proposed for
sensitive measurement applications have invoked the promise of the RF-SET
for fast and ultra-sensitive charge detection. These include Qubits based on
nuclear spins in silicon, charged particle detectors, quantum nanomechanical
oscillations and single terahertz photon counters. It is one of the only
tools for detecting single electron charges at the nanometer scale and with
gigahertz band-width.
In collaboration with the Chalmers and Yale groups, we have made
theoretical analysis and experiments to estimate the
charge sensitivity of a radio frequency single-electron transistor. The
theoretical prediction is based on a model which includes equivalent
circuits for all the components of the measurement system. Low-noise first-stage
amplifier was integrated in the analysis and the noise power wave formalism
was employed in the analysis of the aluminum single-electron transistor test
system.
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The
analyzed measurement setup . a) A carrier wave is guided down to the SET
using the RF IN line. An attenuator of 30 dB and a directional coupler with
13 dB loss attenuate thermal noise. The wave is reflected from the SET with
an LC matching circuit and amplified with a chain of cold and warm
amplifiers. The signal is detected from RF OUT port using a diode detector. |