Wisconsin Quantum Institute |
Events During the Week of January 29th through February 5th, 2023
Monday, January 30th, 2023
- No events scheduled
Tuesday, January 31st, 2023
- No events scheduled
Wednesday, February 1st, 2023
- No events scheduled
Thursday, February 2nd, 2023
- CQE Seminar: Ultrafast quantum simulation and quantum computing with ultracold atom arrays
- Time: 11:00 am - 12:00 pm
- Place: This event is open to Chicago Quantum Exchange Members, Partners, and Trainee. To request attendance, contact quantum@uchicago.edu.
- Speaker: Kenji Ohmori, Institute for Molecular Science, National Institutes of Natural Sciences (NINS), Japan
- Abstract: Many-body correlations drive a variety of important quantum phenomena and quantum machines including superconductivity and magnetism in condensed matter as well as quantum computers. Understanding and controlling quantum many-body correlations is thus one of the central goals of modern science and technology. My research group has recently pioneered a novel pathway towards this goal by exciting strongly interacting ultracold Rydberg atoms, far beyond the Rydberg blockade regime, by using an ultrafast laser pulse. We first applied our ultrafast coherent control with attosecond precision to a random ensemble of those Rydberg atoms in an optical dipole trap, and successfully observed and controlled their strongly correlated electron dynamics on a sub-nanosecond timescale. This new approach is now applied to arbitrary atom arrays assembled with optical lattices or optical tweezers that develop into a pathbreaking platform for quantum simulation and quantum computing on an ultrafast timescale.
In this ultrafast quantum computing, very recently, we have succeeded in executing a controlled-Z gate in only 6.5 nanoseconds. This is the fastest record of a controlled gate, a conditional two-qubit gate essential for quantum computing, faster than any other controlled gates with cold-atom hardware by two orders of magnitude. It is also two orders of magnitude faster than the noise from the external environment and operating lasers, whose timescale is in general 1 microsecond or slower, and thus can be safely isolated from the noise. - Host: CQE
Friday, February 3rd, 2023
- Multi-messenger scanning probe microscopy for the investigation of electronic properties of materials.
- Time: 3:30 pm - 4:30 pm
- Place: 2241 Chamberlin Hall
- Speaker: Victor Brar, UW Madison
- Abstract: Scanning probe microscopy is an imaging technique whereby a sharp tip is moved across a surface while locally measuring some material property with a resolution that can be sub-Angstrom. A wide range of material properties can be studied in this way, including surface conductance (scanning tunneling microscopy), physical structure (atomic force microscopy), and surface potential (Kelvin probe force microscopy). By combining these measurement techniques, a complete understanding of a material's properties can be developed that relates electron motion to underlying atomic structure. In this talk I will show how multiple scanning probe measurements can be performed on graphene to reveal how electrons scatter off and move around in-plane potential barriers formed by charged defects. By comparing measurements of the spatially varying surface potential with measurements of the electron wavefunction, the electron dynamics can be modeled precisely, and described using a single-particle wavefunction. As the electron temperature is increased, however, these measurements reveal a new hydrodynamic phase of the electron fluid emerges with a viscosity comparable to diesel fuel. Our scanned probe measurements show that this new phase exhibits a conductivity that is greater than ballistic conductance, and that the motion of electrons around barriers resembles that of water moving around pebbles in a stream.