DEPARTMENT OF PHYSICS AND ASTRONOMY

Jens Koch’s research interests in theoretical condensed matter physics include strongly correlated quantum systems, quantum information processing with solid-state devices as well as transport and coherence in nanoscale systems.

Classical electric circuits have been perfected in engineering and serve as a major driving force for technological advances. When fabricated of superconducting material, electric circuits can also show quantum behavior. While quantum effects are often considered a nuisance endangering Moore’s law due to limits on miniaturization, physicists have taken a complementary standpoint and have embraced electrical circuits as a new powerful tool for research on fundamental aspects and applications of quantum mechanics.

Koch explores the exciting prospects of applying quantum circuit devices as artificial atoms in quantum computation and quantum optics and, in collaboration with several experimental groups, studies coherence of novel quantum circuits. His second research thrust focuses on larger array systems composed of Josephson-junction based circuits (superconducting qubits) and superconducting microwave resonators. Polaritons in such circuit QED arrays are predicted to undergo quantum phase transitions of polaritons and may lead to quantum simulators of strongly interacting photons.

Awards and Honors

• 2024 APS Fellowship

Selected Publications

• V. Manucharyan, J. Koch, L. I. Glazman, M. H. Devoret, Fluxonium: Single Cooper-Pair Circuit Free of Charge Offsets, Science 326, 113 (2009)
• J. Koch, V. Manucharyan, M. H. Devoret, L. I. Glazman, Charging effects in the inductively shunted Josephson junction, Phys. Rev. Lett. 103, 217004 (2009)
• J. Koch and K. Le Hur, Superfluid–Mott Insulator Transition of Light in the Jaynes-Cummings Lattice, Phys. Rev. A 80, 023811 (2009).
• J. Majer et al., Coupling Superconducting Qubits via a Cavity Bus, Nature 449, 443 (2007)
• J. Koch and F. von Oppen, Franck-Condon Blockade and Giant Fano Factors in Transport through Single Molecules, Phys. Rev. Lett. 94, 206804 (2005)