Quantum amplifier added noise metrology using tunnel junction and diffusive nanowire calibrated noise sources
ORAL
Abstract
The measurement of system noise of ultra-low noise amplifiers requires the use of a well understood noise source with a controllable noise intensity.
Shot-noise tunnel junctions (SNTJ) are a widely used choice, typically constructed from Josephson junctions whose superconductivity is suppressed with strong permanent magnets. Another option is a metallic nanowire of mesoscopic length, a mesoscopic resistor, emitting hot electron shot noise. While the physical mechanism differs between the two, both sources are conceptually equivalent from an experimental perspective. Their noise spectrum depends on an applied dc bias and are self-calibrating: they do not require external thermal calibration. However, the mesoscopic resistor offers a few key advantages. Compared to SNTJs, they are compatible with magnetically sensitive experiments. Additionally, SNTJs have unavoidable parasitic capacitance that attenuates noise at high frequencies. Finally, mesoscopic resistors benefit from a simpler fabrication process.
We present a metrological comparison of these two noise sources under identical experimental conditions to compare (1) their input noise against theoretical expectations and (2) the inferred system noise of a Kinetic Inductance traveling wave parametric amplifier (KIT) chain. A demonstration of near identical results under the same experimental conditions gives confidence in the interchangeability of these sources in characterizing amplifier added noise.
Shot-noise tunnel junctions (SNTJ) are a widely used choice, typically constructed from Josephson junctions whose superconductivity is suppressed with strong permanent magnets. Another option is a metallic nanowire of mesoscopic length, a mesoscopic resistor, emitting hot electron shot noise. While the physical mechanism differs between the two, both sources are conceptually equivalent from an experimental perspective. Their noise spectrum depends on an applied dc bias and are self-calibrating: they do not require external thermal calibration. However, the mesoscopic resistor offers a few key advantages. Compared to SNTJs, they are compatible with magnetically sensitive experiments. Additionally, SNTJs have unavoidable parasitic capacitance that attenuates noise at high frequencies. Finally, mesoscopic resistors benefit from a simpler fabrication process.
We present a metrological comparison of these two noise sources under identical experimental conditions to compare (1) their input noise against theoretical expectations and (2) the inferred system noise of a Kinetic Inductance traveling wave parametric amplifier (KIT) chain. A demonstration of near identical results under the same experimental conditions gives confidence in the interchangeability of these sources in characterizing amplifier added noise.
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Presenters
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Corwin Shiu
- National Institute of Standards and Technology Boulder
- National Institute of Standards and Technology (NIST)