COLLOQUIUM 2025
“Orbital attachment” and the Fractional Quantum Hall Effect
| Speaker | Prof F. Duncan M. Haldane, Princeton University |
| Date/Time | Friday, 17 Jan, 3PM |
| Location | Lecture Theatre 29 |
| Hosts | Antonio (I-FIM) and Ching Hua (Physics). |
| Registration link | https://forms.office.com/r/XSkJvbDyxH |
Abstract
The recent experimental realization of the Fractional Quantum Hall Effect in spontantenously magnetized 2D Moiré Bloch flat bands without a magnetic field, rather than Landau levels in high magnetic fields, prompts a reassesment of the previous Landau-level-centric descriptions of FQHE, based on “flux attachment”.
A new interpretation in terms of “orbital attachment” to form composite bosons appllies equally well to Landau levels and projected Bloch Chern flat bands. Real space “quantum geometry” of the most-localized orbitals of the flat bands, which are fundamentally non-orthogonal, with overlaps that define “quantum distance”, are a key ingredient. These exponentially-localized non-orthogonal Chern-band local orbitals are very different from the exponentially-localized orthogonal Wannier orbitals that can only be constructed in topologically-trivial Bloch bands.
Biography
Prof. Duncan F. Haldane the Sherman Fairchild University Professor of Physics at Princeton University. He is a co-recipient of the 2016 Nobel Prize in Physics, along with David J. Thouless and J. Michael Kosterlitz.
Prof Haldane received his bachelor’s degree from the University of Cambridge in 1973 and a doctorate in physics from the same institution in 1978. He worked as a physicist at Laue-Langevin in Grenoble, France, University of Southern California, Los Angeles, at Bell Laboratories University of California, San Diego before finally to Princeton University.
Prof. Haldane is an elected a Fellow of the Royal Society (FRS) in 1996 and a Fellow of the American Academy of Arts and Sciences (Boston) in 1992;] a Fellow of the American Physical Society (1986) and a Fellow of the Institute of Physics (1996) (UK); a Fellow of the American Association for the Advancement of Science (2001). Prof. Haldane was also elected as a member of the U.S. National Academy of Sciences in 2017, awarded the Oliver E. Buckley Prize of the American Physical Society (1993); Alfred P. Sloan Foundation Research Fellow (1984–88); Lorentz Chair (2008), Dirac Medal (2012); Doctor Honoris Causae of the Université de Cergy-Pontoise (2015); Lise Meitner Distinguished Lecturer (2017); Golden Plate Award of the American Academy of Achievement (2017).
