About the Kaufman Group | JILA - Exploring the Frontiers of Physics

Long-lived entangelement of Bell state pairs compared to single unentangled atoms in a 3D optical lattice. The Bell state "stopwatch" ticks twice as fast than that of a single atom, holding the promise of higher stability and higher bandwidth for optical clocks.

Seeing Quantum Weirdness: Superposition, Entanglement, and Tunneling

A rendering of a ytterbium qubit held within a set of optical tweezers

Tweezing a New Kind of Qubit

optical tweezers holding atoms, connected by a clock

Tweezing a New Kind of Atomic Clock

Figure of trapped and cooled single alkaline-earth atoms.

The Strontium Optical Tweezer

How does classical physics –- such as statistical mechanics — emerge from the collective behavior of quantum mechanical systems? Can we develop new tools for the manipulation of individual particles, such as complex atoms, ions or molecules, whose interactions and internal degrees of freedom establish new prospects for quantum science?

To answer questions like these, our group applies the tools of atomic, molecular, and optical physics to the microscopic study and control of quantum systems, for applications in quantum simulation, quantum information, and metrology. We marry the tools of quantum gas microscopy, optical tweezer technology, and high precision spectroscopy in order to gain single-particle control at fundamental length scales and very small energy scales.

Towards these goals, we trap single alkaline-earth atoms in optical tweezer arrays, a powerful and effective technology that we demonstrated in 2018 for the first time. Optical tweezers allow precise single-particle control, the engineering of different forms of atomic interactions, and high-fidelity atom-resolved readout. However, while previous work with optical tweezers had focused on alkali atoms, the 2018 work opened the door to tweezer-based control of atoms with two electrons in their valence shell -- although a tiny addition, this additional electron gives rise to the rich internal structure of alkaline-earth atoms, which underlies their applications in metrology, quantum simulation, and quantum information. In this lab, we apply the microscopic control capabilities emerging from the optical tweezer toolset to the quantum science directions that emerge from the use of alkaline-earth atoms.

Research Areas

Quantum Metrology with Tweezer Clocks
One of the scientific pursuits for which alkaline-earth atoms are most famous is optical atomic clocks. In atoms like Strontium and Ytterbium, there exists a long-lived optical transition known as the “clock transition”. Viewed as an oscillator, this transition has an intrinsic quality factor of in excess of 10¹⁷— that is, it can ring quadrillions of times before the oscillations die out. This means this oscillator can serve as an exceptional time-keeper, and, indeed, in the past decade, such optical atomic clocks have allowed some of the most precise measurements ever made by humans.

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Assembled Hubbard Systems of Alkaline-earth Atoms
Another appealing aspect of alkaline-earth atoms is the presence of a second relatively narrow transition — though not as narrow as the clock transition — that can be used for ground-state laser cooling. This is especially powerful when combined with the possibility of rearranging optical tweezers to prepare arbitrary atomic distributions with very low entropy in the atomic spatial distribution. So far, large-scale demonstrations of atomic rearrangement have been used for spin models, with atoms that might be relatively hot in their motional degrees of freedom. In this project, we seek to prepare arbitrary distributions of scalable arrays of ground-state atoms for large scale itinerant models.

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Quantum Simulation and Information with Ytterbium Tweezer Arrays
Unlike their bosonic counterpart, fermionic isotopes of alkaline-earth atoms benefit from having nuclear spin. This spin has been proposed for new many-body models, such as SU(N) physics, as well as the basis for new qubit architectures. In a new experiment, we seek to gain single-qubit-resolved control of arrays of Ytterbium-171 atoms, where quantum information is stored in the spin-1/2 nuclear spin of this isotope. We seek to engineer the resulting system to fully exploit the high two-qubit gate speeds possible with large Rydberg Rabi frequencies from the excited clock state.

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In the Spotlight

JILA Fellow and NIST Physicist Adam Kaufman at work in his lab

December 14, 2022: JILA Fellow and NIST Physicist Adam Kaufman is awarded a grant from the 2023 Young Investigator Research Program

JILA Fellow, NIST Physicist, and University of Colorado Physics professor Adam Kaufman has been awarded a grant as part of the 2023 Young Investigator Research Program, or YIP. YIP was launched by the Air Force Office of Scientific Research, or AFOSR, the basic research arm of the Air Force Research Laboratory. The AFOSR's mission is to support Air Force goals of control and maximum utilization of air, space, and cyberspace. To do this, AFSOR is awarding $25 million in grants to 58 scientists and engineers from 44 research institutions and businesses in 22 states in 2023.

November 30, 2022: JILA Graduate Student Aaron Young is Awarded a 2022 University of Chicago Quantum Creators Prize

JILA graduate student Aaron Young, a researcher in JILA Fellow and NIST Physicist Adam Kaufman’s laboratory has been awarded a 2022 University of Chicago Quantum Creators Prize. The prize is part of the Chicago Quantum Exchange, one of the largest organizations celebrating quantum research and computing in the U.S. As Young explained: “This award is relatively new, this is only the second year it's been around, but I think it does a good job of providing some visibility to junior people in the field - particularly to people outside the academic community like those in industry or in government.” To promote early career research and diversity within the field of quantum science, award winners receive an honorarium of $500, a prize certificate, and reimbursed travel to the 2022 Chicago Quantum Summit.

JILA Fellow Adam Kaufman wins the 2023 I.I. Rabi Prize in AMO Physics

October 11, 2022: JILA Fellow and NIST Physicist Adam Kaufman is awarded the 2023 I.I. Rabi Prize in Atomic, Molecular, and Optical Physics

Adam Kaufman — a JILA Fellow, NIST (National Institute of Standards and Technology) Physicist, and University of Colorado Boulder Professor — has been awarded the American Physical Society's (APS) 2023 I.I. Rabi Prize in Atomic, Molecular, and Optical (AMO) physics.

JILA and NIST Fellow Adam Kaufman in his lab

September 22, 2022: JILA and NIST Fellow Adam Kaufman Wins Breakthrough New Horizons in Physics Prize

Boulder, Colo. — Physicist Adam Kaufman of both JILA and the U.S. Department of Commerce’s National Institute of Standards and Technology (NIST) has been awarded the 2023 New Horizons in Physics Prize from the Breakthrough Prize Foundation for his work in advancing the control of atoms and molecules to improve atomic clocks and quantum information processing.

JILA Address

We are located at JILA: A joint institute of NIST and the University of Colorado Boulder.

Map | JILA Phone: 303-492-7789 | Address: 440 UCB, Boulder, CO 80309