Publications
Comparison of gate dielectric plasma damage from plasma-enhanced atomic layer deposited and magnetron sputtered TiN metal gates
Summary
Summary
Fully depleted silicon-on-insulator transistors were fabricated using two different metal gate deposition mechanisms to compare plasma damage effects on gate oxide quality. Devices fabricated with both plasma-enhanced atomic-layer-deposited (PE-ALD) TiN gates and magnetron plasma sputtered TiN gates showed very good electrostatics and short-channel characteristics. However, the gate oxide quality was...
Thermal and residual excited-state population in a 3D transmon qubit
Summary
Summary
Remarkable advancements in coherence and control fidelity have been achieved in recent years with cryogenic solid-state qubits. Nonetheless, thermalizing such devices to their milliKelvin environments has remained a long-standing fundamental and technical challenge. In this context, we present a systematic study of the first-excited-state population in a 3D transmon superconducting...
Fabrication process and properties of fully planarized deep-submicron Nb/Al-AlOx/Nb Josephson junctions for VLSI circuits
Summary
Summary
A fabrication process for Nb/Al-AlOx/Nb Josephson junctions (JJs) with sizes down to 200 nm has been developed on a 200-mm-wafer tool set typical for CMOS foundry. This process is the core of several nodes of a roadmap for fully-planarized fabrication processes for superconductor integrated circuits with 4, 8, and 10...
Inductance of circuit structures for MIT LL superconductor electronics fabrication process with 8 niobium layers
Summary
Summary
Inductance of superconducting thin-film inductors and structures with linewidth down to 250 nm has been experimentally evaluated. The inductors include various striplines and microstrips, their 90 degree bends and meanders, interlayer vias, etc., typically used in superconducting digital circuits. The circuits have been fabricated by a fully planarized process with...
Broadband magnetometry and temperature sensing with a light-trapping diamond waveguide
Summary
Summary
Solid-state quantum sensors are attracting wide interest because of their sensitivity at room temperature. In particular, the spin properties of individual nitrogen-vacancy (NV) colour centres in diamond make them outstanding nanoscale sensors of magnetic fields, electric fields and temperature under ambient conditions. Recent work on NV ensemble-based magnetometers, inertial sensors...
Measurement of ion motional heating rates over a range of trap frequencies and temperatures
Summary
Summary
We present measurements of the motional heating rate of a trapped ion at different trap frequencies and temperatures between ~0.6 and 1.5 MHz and ~4 and 295 K. Additionally, we examine the possible effect of adsorbed surface contaminants with boiling points below ~105 degrees C by measuring the ion heating...
Increasing the coherence time in a magnetically-sensitive stimulated Raman transition in 85Rb
Summary
Summary
We experimentally study the Ramsey, spin echo, and CPMG pulse sequences of a magnetically sensitive transition of a cold 85Rb gas. We can increase the coherence time by up to a factor of 10 by using CPMG pulse sequences as compared to Ramsey or spin echo.
Energy efficiency benefits of subthreshold-optimized transistors for digital logic
Summary
Summary
The minimum energy point of an integrated circuit (IC) is defined as the value of the supply voltage at which the energy per operation of the circuit is minimized. Several factors influence what the value of this voltage can be, including the topology of the circuit itself, the input activity...
Silicon photonics devices for integrated analog signal processing and sampling
Summary
Summary
Silicon photonics offers the possibility of a reduction in size weight and power for many optical systems, and could open up the ability to build optical systems with complexities that would otherwise be impossible to achieve. Silicon photonics is an emerging technology that has already been inserted into commercial communication...
A tunable AC atom interferometer magnetometer
Summary
Summary
We demonstrate an atom interferometer designed to measure magnetic fields and field gradients. Here, we study various pulse sequences and show how they can be manipulated to filter unwanted frequencies and to enhance desired frequencies.