Offset charges acting as excited states in quantum dots spectroscopy (2008)
Pierre, M., Hofheinz, M., Jehl, X., Sanquer, M., Molas, G., Vinet, M., ...
We have performed Coulomb blockade spectroscopy in silicon quantum dots and observed characteristic features in the differential conductance. In particular well defined lines in the Coulomb diamonds,...
Measurement of the decay of Fock states in a superconducting quantum circuit (2008)
Wang, H., Hofheinz, M., Ansmann, M., Bialczak, R. C., Lucero, E., Neeley, M., ...
We demonstrate the controlled generation of Fock states with up to 15 photons in a microwave coplanar waveguide resonator coupled to a superconducting phase qubit. The subsequent decay of the Fock...
Uncollapsing of a quantum state in a superconducting phase qubit (2008)
Katz, Nadav, Neeley, Matthew, Ansmann, M., Bialczak, Radoslaw C., Hofheinz, M., Lucero, Erik, ...
We demonstrate in a superconducting qubit the conditional recovery ("uncollapsing") of a quantum state after a partial-collapse measurement. A weak measurement extracts information and results in a...
Microwave Dielectric Loss at Single Photon Energies and milliKelvin Temperatures (2008)
O'Connell, Aaron D., Ansmann, M., Bialczak, R. C., Hofheinz, M., Katz, N., Lucero, Erik, ...
The microwave performance of amorphous dielectric materials at very low temperatures and very low excitation strengths displays significant excess loss. Here, we present the loss tangents of some...
High-fidelity gates in a Josephson qubit (2008)
Lucero, Erik, Hofheinz, M., Ansmann, M., Bialczak, Radoslaw C., Katz, N., Neeley, Matthew, ...
We demonstrate new experimental procedures for measuring small errors in a superconducting quantum bit (qubit). By carefully separating out gate and measurement errors, we construct a complete error...
Transformed Dissipation in Superconducting Quantum Circuits (2008)
Neeley, Matthew, Ansmann, M., Bialczak, Radoslaw C., Hofheinz, M., Katz, N., Lucero, Erik, ...
Superconducting quantum circuits must be designed carefully to avoid dissipation from coupling to external control circuitry. Here we introduce the concept of current transformation to quantify...
1/f Flux Noise in Josephson Phase Qubits (2007)
Bialczak, Radoslaw C., McDermott, R., Ansmann, M., Hofheinz, M., Katz, N., Lucero, Erik, ...
We present a new method to measure 1/f noise in Josephson quantum bits (qubits) that yields low-frequency spectra below 1Hz. Comparison of noise taken at positive and negative bias of a phase qubit...
Hofheinz, M., Jehl, X., Sanquer, M., Molas, G., Vinet, M., Deleonibus, S.
A simple and highly reproducible single electron transistor (SET) has been fabricated using gated silicon nanowires. The structure is a metal-oxide-semiconductor field-effect transistor made on...
Hofheinz, M., Jehl, X., Sanquer, M., Molas, G., Vinet, M., Deleonibus, S.
We study anomalies in the Coulomb blockade spectrum of a quantum dot formed in a silicon nanowire. These anomalies are attributed to electrostatic interaction with charge traps in the device. A...
Size scaling of the addition spectra in silicon quantum dots (2004)
Bohm, M., Hofheinz, M., Jehl, X., Sanquer, M., Vinet, M., Previtali, B., ...
We investigate small artificial quantum dots obtained by geometrically controlled resistive confinement in low mobility silicon-on-insulator nanowires. Addition spectra were recorded at low...