Mark W Keller | National Institute of Standards and Technology (original) (raw)

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Papers by Mark W Keller

Journal of low temperature physics, May 19, 2024

Bulletin of the American Physical Society, Mar 12, 2008

Applied Physics Letters, Aug 21, 2006

APS March Meeting Abstracts, Mar 1, 1997

ABSTRACT Fluctuations in the background charges of the tunnel junctions in the electron pump limi... more ABSTRACT Fluctuations in the background charges of the tunnel junctions in the electron pump limit the accuracy of the device over long times. We have measured the background charge on each junction as follows. We create a charge bias by applying voltages of opposite polarity to the gates on either side of the junction. As this bias is swept from 0 to e, the junction allows tunneling when the sum of the background charge and the applied charge is equal to 0.5e. Thus if tunneling occurs at an applied bias of 0.6e, we infer a background charge of -0.1e. Since the tunneling signal is thermally broadened, the measurement also yields the electron temperature of the junctions. We report several results based on this technique. 1) The rate and amplitude of the background charge fluctuations decrease over a period of about 2 weeks at 40 mK. 2) The electron temperature follows the refrigerator temperature down to 40 mK. This shows conclusively that electron heating cannot explain our earlier observation that pump accuracy is independent of temperature below 100 mK. 3) Using the known temperature, we infer the total capacitance of each junction and find nearly the same value for all junctions. These results significantly improve our ability to compare our observed error rates with theory.

Bulletin of the American Physical Society, Mar 18, 2013

Physica E-low-dimensional Systems & Nanostructures, Mar 1, 2004

Physical Review Letters, May 18, 1998

Physical review, Apr 30, 2003

Physical review, Sep 15, 1999

Physical review, Dec 15, 2000

Physical Review Letters, May 29, 2000

APS March Meeting Abstracts, Mar 1, 2003

We are studying the tunneling of individual electrons into self-assembled InAs quantum dots with ... more We are studying the tunneling of individual electrons into self-assembled InAs quantum dots with single-electron transistors. Aluminum single-electron transistors were fabricated over an epitaxial structure including self-assembled InAs quantum dots and an underlying n-doped layer. Sweeping the potential on the n-doped layer causes individual electrons to tunnel onto a quantum dot, and is detected capacitively with a single electron transistor.