James Shaffer



Regents' Award for Superior Research & Creative Activity

Presidential Professorship

Humboldt Prize



B.S. 1991 University of Illinois at Urbana-Champaign

Ph.D. 1999 University of Rochester



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Ph: (405) 325-6656

Office: 143 Nielsen Hall


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Research Area

Atomic, Molecular and Optical Physics

Research Description

I am currently interested in investigating exotic states of matter and the coupling of quantum dynamical systems to their environment. My research group has developed novel experimental methods for investigating the interactions between ultracold atoms using Rydberg atom time-of-flight spectroscopy. In developing this method, we were able to predict and find a new type of molecule formed by 2 Rydberg atoms which has a bond length of > 3 μm. I am also interested in other types of molecules that can form at ultralow temperatures such as Rydberg atom-ground state atom molecules and the physics of Efimov states and three-body recombination. These types of systems and methods are important for investigating chemical dynamics that can take place in ultracold atom traps. My research group also is working on understanding the interactions between cold Rydberg atoms for making new types of quantum entanglement based devices such as single photon sources and quantum gates. Some of this work is done at ultracold temperatures, where T ≤ 1 mK, and some is done in thermal vapor cells. Our work in thermal vapor cells is directed at developing an electric field standard and sensor for microwave fields that is based on atoms. Most of these investigations are experimental but my research group also does theory to support our experimental efforts.


"Microwave Electrometry using Rydberg Atomic Prism via Electromagnetically Induced Transparency," H. Fan, S. Kumar, H. Kubler, and J. P. Shaffer, J. Phys. B: At. Mol. Opt. Phys. , 49, 104004, (2016) DOI: http://iopscience.iop.org/article/10.1088/0953-4075/49/10/104004/pdf

"Collective state synthesis in an optical cavity using Rydberg atom blockade," S. Kumar, J. Sheng, J. Sedlacek, H.Q. Fan, and J.P. Shaffer, J. Phys. B: At. Mol. Opt. Phys., 49, 064014, (2016) DOI: http://iopscience.iop.org/article/10.1088/0953-4075/49/6/064014/pdf

"Effect of Vapor Cell Geometry on Rydberg Atom-based Radio-frequency Electrometry," H. Fan, S. Kumar, J. Sheng, C. L. Holloway and J. A. Gordon, J. P. Shaffer, Phys. Rev. Applied , 4, 044015, (2015) DOI: https://journals.aps.org/prapplied/abstract/10.1103/PhysRevApplied.4.044015

"Atom based RF electric field sensing," H.Q. Fan, S. Kumar, J. Sedlacek, H. Kubler, S. Karimkashi, and J.P. Shaffer, J. Phys. B: At. Mol. Opt. Phys. , 48, 202001, (2015)

"Atom-based RF Electric Field Measurements: An Initial Investigation of the Measurement Uncertainties," C. L. Holloway, J. A. Gordon, M. T. Simons, H. Fan, S. Kumar, J. P. Shaffer, D. A Anderson, A. Schwarzkopf, S. A. Miller, N. Thaicharoen and G. Raithel, IEEE Electromagnetic Compatibility (EMC), 467, (2015)

"Effects of Vapor Cell Size on Rydberg Atom Electrometry," H.Q. Fan, S. Kumar, C. Holloway, J. Gordon and J.P. Shaffer, Physical Review Applied, 4, 044015, (2015)

"Rydberg atom-based electric field sensing from radio to terahertz frequencies," H.Q. Fan, S. Kumar, H. Kubler, S. Karimkashi and J.P. Shaffer, Journal of Physics B, 48, 202001, (2015)

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