The superconducting quantum computing architecture has seen rapid improvements over the last two decades. However, the coherence time of superconducting qubits is limited by unknown noise sources presumably existent at the interface between the insulator and the superconducting film. Carbon nanotubes (CNTs) are a promising material for use in Josephson-Junctions (JJs) given their unique properties, such as high electrical conductivity, pristine surface, inherent nanoscale dimension, and silicon-compatible processing. In this project, we are building gate-controlled JJs composed of CNT thin films (down-to-monolayer) positioned between two superconducting electrodes to act as a promising superconducting qubit for quantum computers. Aside from gate-controllability, this approach offers superb interface engineering capability, small integration footprint, and high-temperature operation. We expect the CNT film – JJ superconducting qubit will achieve superior performance relative to current state-of-the-art JJs and enable the development of scalable superconducting computation with extensions to arrays of CNT-JJs coupled to microwave and optical photon-waveguides.
Figure 1. Cooper pairs interacting with gate-controlled Jospehson-Junctions composed of CNT thin films
Applications of Neutron Interferometry and Structured Neutron Beams
Summary Neutrons are a powerful probe of matter and physics due to their Angstrom size wavelengths, electric neutrality and relatively large mass. In this project, we develop quantum sensors that exploit these attributes to increases the precision of measurements of fundamental forces and materials structure. With David Cory, Alexander Cronin of the University of Arizona, […]
July 31, 2018
Next Generation Quantum Sensors
We are developing new semiconductor p-n junctions and designing novel nanowire arrays that have the potential to significantly enhance the ability to detect light at the single photon level over an unprecedented wavelength range from the ultraviolet to infrared.
June 1, 2017
Developing Tools for Quantum Characterization and Validation
Summary Coherence is essential for quantum computation; yet it introduces a unique sensitivity to any imperfections in hardware design, control systems, and the operating environment. Overcoming these sensitivities requires a hierarchy of strategies, ranging from optimization of the hardware architecture to software solutions including quantum error correction. Randomized Benchmarking Protocols are an important family of […]
October 3, 2017
Ultrafast Dynamical Studies of Valley-Based Qubits
Summary As monolayers, transition metal dichalcogenides (TMDCs) – such as tungsten diselenide (WSe2) – become direct-bandgap semiconductors capable of emitting light. Compared to conventional direct-bandgap semiconductors, such as III-V semiconductors like GaAs, excitons (quasiparticles made of an electron hole bound with an electron) and single-layer TMDCs (SL-TMDCs) have much stronger binding energy. Excitons and […]
June 29, 2018