title: An incompressible state of a photo-excited electron gas.
abstract: Two-dimensional electrons in a magnetic field can form new states of matter characterized by topological properties and strong electronic correlations as displayed in the integer and fractional quantum Hall states. In these states, the electron liquid displays several spectacular characteristics, which manifest themselves in transport experiments with the quantization of the Hall resistance and a vanishing longitudinal conductivity or in thermodynamic equilibrium when the electron fluid becomes incompressible. Several experiments have reported that dissipationless transport can be achieved even at weak, non-quantizing magnetic fields when the electrons absorb photons at specific energies related to their cyclotron frequency. Here we perform compressibility measurements on electrons on liquid helium demonstrating the formation of an incompressible electronic state under these resonant excitation conditions. This new state provides a striking example of irradiation-induced self-organization in a quantum system.
authors.affiliation: 1] LPS, Université Paris-Sud, CNRS, UMR 8502, Orsay F-91405, France [2] Cavendish Laboratory, University of Cambridge, J J Thomson Avenue, Cambridge CB3 OHE, UK.
authors.forename: Alexei D
authors.initials: AD
authors.lastname: Chepelianskii
authors.affiliation: Low Temperature Physics Laboratory, RIKEN, Wako, Saitama 351-0198, Japan.
authors.forename: Masamitsu
authors.initials: M
authors.lastname: Watanabe
authors.affiliation: Quantum Condensed Phases Research Team, RIKEN CEMS, Wako, Saitama 351-0198, Japan.
authors.forename: Kostyantyn
authors.initials: K
authors.lastname: Nasyedkin
authors.affiliation: 1] Quantum Condensed Phases Research Team, RIKEN CEMS, Wako, Saitama 351-0198, Japan [2] Institute of Physics, National Chiao Tung University, Hsinchu 30010, Taiwan [3] Institute of Physics, Kazan Federal University, Kazan 420008, Russia.
authors.forename: Kimitoshi
authors.initials: K
authors.lastname: Kono
authors.affiliation: Okinawa Institute of Science and Technology, Onna, Okinawa 904-0412, Japan.
authors.forename: Denis
authors.initials: D
authors.lastname: Konstantinov