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Silicon Quantum Dots with Counted Antimony Donor Implants

Sandia journal manuscript; Not yet accepted for publication

Singh, Meenakshi S.; Pacheco, Jose L.; Perry, Daniel L.; Ten Eyck, Gregory A.; Wendt, J.R.; Pluym, Tammy P.; Dominguez, Jason J.; Manginell, Ronald P.; Luhman, Dwight R.; Bielejec, Edward S.; Lilly, Michael L.; Carroll, Malcolm

Deterministic control over the location and number of donors is crucial to donor spin quantum bits (qubits) in semiconductor based quantum computing. A focused ion beam is used to implant close to quantum dots. Ion detectors are integrated next to the quantum dots to sense the implants. The numbers of ions implanted can be counted to a precision of a single ion. Regular coulomb blockade is observed from the quantum dots. Charge offsets indicative of donor ionization, are observed in devices with counted implants.

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TYPE Journal Article YEAR 2015
OSTI

Mechanical Flip-Chip for Ultra-High Electron Mobility Devices

Scientific Reports

Bennaceur, Keyan; Schmidt, Benjamin A.; Gaucher, Samuel; Laroche, D.; Lilly, Michael L.; Reno, J.L.; West, Ken W.; Pfeiffer, Loren N.; Gervais, Guillaume

Electrostatic gates are of paramount importance for the physics of devices based on high-mobility two-dimensional electron gas (2DEG) since they allow depletion of electrons in selected areas. This field-effect gating enables the fabrication of a wide range of devices such as, for example, quantum point contacts (QPC), electron interferometers and quantum dots. To fabricate these gates, processing is usually performed on the 2DEG material, which is in many cases detrimental to its electron mobility. Here we propose an alternative process which does not require any processing of the 2DEG material other than for the ohmic contacts. This approach relies on processing a separate wafer that is then mechanically mounted on the 2DEG material in a flip-chip fashion. This technique proved successful to fabricate quantum point contacts on both GaAs/AlGaAs materials with both moderate and ultra-high electron mobility.

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TYPE Journal Article YEAR 2015
ScopusOSTIDOI

Charge Sensed Pauli Blockade in a Metal–Oxide–Semiconductor Lateral Double Quantum Dot

Nano Letters

Nguyen, Khoi T.; Lu, Tzu-Ming L.; Muller, Richard P.; Carroll, Malcolm; Lilly, Michael L.; Nielsen, Erik N.; Bishop, Nathaniel B.; Young, Ralph W.; Wendt, J.R.; Dominguez, Jason J.; Pluym, Tammy P.; Stevens, Jeffrey S.

We report Pauli blockade in a multielectron silicon metal–oxide–semiconductor double quantum dot with an integrated charge sensor. The current is rectified up to a blockade energy of 0.18 ± 0.03 meV. The blockade energy is analogous to singlet–triplet splitting in a two electron double quantum dot. Built-in imbalances of tunnel rates in the MOS DQD obfuscate some edges of the bias triangles. A method to extract the bias triangles is described, and a numeric rate-equation simulation is used to understand the effect of tunneling imbalances and finite temperature on charge stability (honeycomb) diagram, in particular the identification of missing and shifting edges. A bound on relaxation time of the triplet-like state is also obtained from this measurement.

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TYPE Journal Article YEAR 2013
OSTIDOI
Results 51–100 of 195
Results 51–100 of 195