Wisconsin Quantum Institute

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Events During the Week of January 30th through February 6th, 2022

Monday, January 31st, 2022

No events scheduled

Tuesday, February 1st, 2022

Coherent Control of Processes that Break the Dipole Blockade
Time: 11:00 am - 12:00 pm
Speaker: Aaron Reinhard, Kenyon College
Abstract: The Rydberg excitation blockade has enabled impressive achievements in quantum information and simulation. However, unwanted processes may compromise the single-excitation behavior of the blockade and reduce its efficiency. We study one such process, state-mixing interactions. When ultracold atoms are excited to Rydberg states near Förster resonance, up to ∼ 50% of the detected atoms can be found in dipole-coupled product states within tens of ns of excitation. There has been disagreement in the literature regarding the mechanism by which this mixing occurs.

We use state-selective field ionization spectroscopy with single-event resolution to probe state mixing near the 43D5/2 Förster resonance in Rb. Our method allows us to control the mechanism by which state-mixing interactions occur during Rydberg excitation. Additionally, we use a rotary echo technique to demonstrate the coherence of the evolution of mixed three-particle states during our Rydberg excitation pulses. The ability to coherently control state-mixing events will allow experimenters to avoid this unwanted process when implementing quantum devices using neutral atoms.
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Wednesday, February 2nd, 2022

No events scheduled

Thursday, February 3rd, 2022

Time: 10:00 am - 11:00 am
Speaker: Andrei Derevianko, University of Nevada, Reno
Abstract: CANCELLED.
Host: Mark Saffman
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Time: 4:00 pm - 5:00 pm
Place: Cancelled
Speaker: Justyna Zwolak, NIST
Abstract: Cancelled
Host: Mark Eriksson
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Friday, February 4th, 2022

Quantum computing with neutral Yb atoms
Time: 3:30 pm
Place: 2241 Chamberlin Hall
Speaker: Jeff Thompson, Princeton
Abstract: Quantum computing with neutral atoms has progressed rapidly in recent years, combining large system sizes, flexible and dynamic connectivity, and quickly improving gate fidelities. The pioneering work in this field has been implemented using alkali atoms, primarily rubidium and cesium. However, divalent, alkaline-earth-like atoms such as ytterbium offer significant technical advantages. In this talk, I will present our progress on quantum computing using 171-Yb atoms, including high-fidelity imaging, nuclear spin qubits with extremely long coherence times, and two-qubit gates on nuclear spins using Rydberg states [1,2]. I will also discuss several unexpected benefits of alkaline-earth-atoms: an extremely robust and power-efficient local gate addressing scheme [3], and a novel approach to quantum error correction called “erasure conversion”, which has the potential to implement the surface code with a threshold exceeding 4%, using the unique level structure of 171-Yb to convert spontaneous emission events into erasure errors [4]. Time permitting, I will also discuss a new project to implement very high fidelity quantum computing and simulation using circular Rydberg states with 100-second lifetimes [5]. [1] S. Saskin et al, Phys. Rev. Lett. 122, 143002 (2019). [2] A. P. Burgers et al, arXiv:2110.06902 (2021). [3] S. Ma, A. P. Burgers, et al, arXiv: 2112.06799 (2021). [4] Y. Wu, et al: arXiv:2201.03540 (2022). [5] S. R. Cohen et al, PRX Quantum 2, 030322 (2021).
Host: Shimon Kolkowitz
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