title: Critical slowing down of the charge carrier dynamics at the Mott metal-insulator transition.
abstract: We report on the dramatic slowing down of the charge carrier dynamics in a quasi-two-dimensional organic conductor, which can be reversibly tuned through the Mott metal-insulator transition (MIT). At the finite-temperature critical end point, we observe a divergent increase of the resistance fluctuations accompanied by a drastic shift of spectral weight to low frequencies, demonstrating the critical slowing down of the order parameter (doublon density) fluctuations. The slow dynamics is accompanied by non-Gaussian fluctuations, indicative of correlated charge carrier dynamics. A possible explanation is a glassy freezing of the electronic system as a precursor of the Mott MIT.
authors.affiliation: Institute of Physics and SFB/TR 49, Goethe-University Frankfurt, 60438 Frankfurt (M), Germany.
authors.forename: Benedikt
authors.initials: B
authors.lastname: Hartmann
authors.affiliation: Institute of Physics and SFB/TR 49, Goethe-University Frankfurt, 60438 Frankfurt (M), Germany.
authors.forename: David
authors.initials: D
authors.lastname: Zielke
authors.affiliation: Institute of Physics and SFB/TR 49, Goethe-University Frankfurt, 60438 Frankfurt (M), Germany.
authors.forename: Jana
authors.initials: J
authors.lastname: Polzin
authors.affiliation: Institute for Materials Research, Tohoku University, Sendai 980-8577, Japan.
authors.forename: Takahiko
authors.initials: T
authors.lastname: Sasaki
authors.affiliation: Institute of Physics and SFB/TR 49, Goethe-University Frankfurt, 60438 Frankfurt (M), Germany.
authors.forename: Jens
authors.initials: J
authors.lastname: Müller