R. G. Herb Condensed Matter Seminars |
Events During the Week of August 30th through September 6th, 2026
Monday, August 31st, 2026
- No events scheduled
Tuesday, September 1st, 2026
- No events scheduled
Wednesday, September 2nd, 2026
- No events scheduled
Thursday, September 3rd, 2026
- Strongly anharmonic flux-tunable transmon based on InAs-Al two-dimensional heterostructure
- Time: 10:00 am - 6:00 pm
- Place: 5310 Chamberlin Hall
- Speaker: Arunav Bordoloi, NYU
- Abstract: Superconducting qubits inherently face a longstanding tradeoff between anharmonicity and susceptibility to charge noise - a limitation that affects even state-of-the-art transmons and gatemons. In this talk, I will present a flux-frustrated transmon architecture [1] that overcomes this tradeoff by exploiting the interference of higher-order harmonics in highly transparent epitaxial Al-InAs Josephson junctions. Using this approach, we experimentally demonstrate anharmonicity exceeding 100% and reaching up to 800% of the qubit transition frequency at the half-integer flux sweet spot, without introducing additional sensitivity to offset-charge noise. The resulting large anharmonicity enables raw Rabi frequencies exceeding 100 MHz without complex pulse shaping, providing a simple and robust route toward faster qubit control. I will then discuss our ongoing efforts to extend this platform toward higher-temperature operation, with the goal of realizing superconducting qubits near 1 Kelvin to facilitate the scaling of quantum hardware. Finally, I will present preliminary results on gate-tunable superconductor–insulator transitions in epitaxial Al-InAs heterostructures, demonstrating the broader potential of this platform for exploring dissipative quantum phenomena and electrically tunable superconducting devices. [1] S. Liu*, A. Bordoloi* et al., Nature Communications 17, 740 (2026)
- Host: Roman Kuzmin
Friday, September 4th, 2026
- No events scheduled