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Search Publications by: Mark Keller (Fed)

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Displaying 26 - 50 of 69

Current Status of the Quantum Metrology Triangle

January 18, 2008
Author(s)
Mark W. Keller
The quantum metrology triangle is a test of the consistency of three quantum electrical standards: the single-electron tunneling current standard, the Josephson voltage standard, and the quantum Hall resistance standard. This paper considers what is known

Uncertainty budget for the NIST Electron Counting Capacitance Standard, ECCS- 1

November 21, 2007
Author(s)
Mark W. Keller, Neil M. Zimmerman, Ali L. Eichenberger
We measure a cryogenic, vacuum-gap capacitor by two methods: 1) charging it with a known number of electrons and measuring the resulting voltage, and 2) using a capacitance bridge traceable to the SI farad. We report a detailed uncertainty budget for the

A single-photon pump

August 25, 2006
Author(s)
Kevin Osborn, Mark W. Keller
We describe a gated quantum dot device called a single-photon pump that produces single photons on demand through the controlled tunneling of individual electrons and holes. Simulations using an InGaAs/GaAs dot show that two modes of operation are possible

HEMT Amplified SET Measurements of Individual InGaAs Quantum Dots

August 25, 2006
Author(s)
Kevin Osborn, Mark W. Keller, Richard Mirin
A High Electron Mobility Transistor (HEMT) is used with a Single Electron Transistor (SET) to measure single electrons tunnelling into individual InGaAs quantum dots. The SET detects the charge motion as an electron tunnels from an underlying n-doped layer

VARIABILITY OF CHARGE NOISE IN Al-BASED SET TRANSISTORS

July 14, 2006
Author(s)
Mark W. Keller, Blaise Jeanneret, Joe Aumentado
We measured the charge noise of four Al-based SET transistors on multiple cooldowns. We found a consistent 1/f component independent of thermal cycling and other treatments, but large variations in the total noise spectrum due to two-level fluctuators.

Single-electron transistor spectroscopy of InGaAs self-assembled quantum dots

March 1, 2004
Author(s)
Kevin Osborn, Mark W. Keller, Richard Mirin
A single-electron transistor (SET) is used to detect tunneling of single electrons into individual InGaAs self-assembled quantum dots (QDs). By using an SET with a small island area and growing QDs with a low density we are able to distinguish and measure

Nonequilibrium Quasiparticles and Periodicity in Single-Cooper-Pair Transistors

February 13, 2004
Author(s)
Joe Aumentado, Mark W. Keller, John M. Martinis, Michel H. Devoret
We have made single-Cooper-pair transistors in which we control the spatial profile of the superconducting gap energy by oxygen doping. The profile dramatically affects the switching current vs. gate voltage curve of the transistor, changing its period

Single-Electron Transistor Spectroscopy of InGaAs Self-Assembled Quantum Dots

January 1, 2004
Author(s)
Kevin Osborn, Mark W. Keller, Richard Mirin
A single-electron transistor is used to detect tunneling of single electrons into self-assembled InGaAs quantum dots. Aluminum single-electron transistors (SETs) are fabricated over an MBE-grown structure containing quantum dots (QDs) and an underlying n

Electrical metrology with single electrons

July 16, 2003
Author(s)
Neil M. Zimmerman, Mark W. Keller
This paper is mostly a review of the progress made at NIST in pursuing a capacitance standard based on the charge of the electron. We briefly introduce the Coulomb blockade, which is the basic physical phenomenon allowing control of single electrons

Counting Errors in a Voltage-Biased Electron Pump

April 30, 2003
Author(s)
Xavier Jehl, Mark W. Keller, Richard L. Kautz, Joe Aumentado, John M. Martinis
We have measured the counting errors of a 7-junction electron pump when charge is pumped against a voltage difference. At voltages above about 50 υV, we find that the errors increase exponentially with both pump voltage and temperature, in agreement with

A Seven Junction Cooper Pair Pump

February 15, 2003
Author(s)
Joe Aumentado, Mark W. Keller, John M. Martinis
We have measured current-voltage curves and individual charge transfer events in single-Cooper-pair pumps. We observe clear charge pumping in units of 2e, but this behavior is accompanied by significant effects from unwanted quasiparticles.

Single-Cooper-Pair Transistors: Requirements for Robust 2e Periodicity

January 3, 2003
Author(s)
Joe Aumentado, Mark W. Keller, John M. Martinis
The superconducting analog of the single-electron transistor (SET), the single-Cooper-pair transistor (SCPT), is comprised of two ultrasmall tunnel junctions in series forming an island (see Figure 1(a)). Transport through the SCPT depends on the

Bimodal Size Distribution of Self-Assembled InGaAs Quantum Dots

September 23, 2002
Author(s)
Solveig Anders, C. S. Kim, Benjamin D. Klein, Mark W. Keller, Richard Mirin
We investigate energy level quantization in self-assembled InGaAs quantum dots that are embedded In a GaAs matrix. We use capacitance and photoluminescence spectroscopy to analyze the evolution of the energy levels with varying amounts of deposited InGaAs

Noise-Induced Leakage and Counting Errors in the Electron Pump

December 15, 2000
Author(s)
Richard L. Kautz, Mark W. Keller, John M. Martinis
Computer simulations reveal that the lowest rates of leakage and counting errors observed in the electron pump can be explained by photon-assisted tunneling driven by 1/f noise. The noise power at microwave frequencies required to account for the observed