title: Athermal domain-wall creep near a ferroelectric quantum critical point.
abstract: Ferroelectric domain walls are typically stationary because of the presence of a pinning potential. Nevertheless, thermally activated, irreversible creep motion can occur under a moderate electric field, thereby underlying rewritable and non-volatile memory applications. Conversely, as the temperature decreases, the occurrence of creep motion becomes less likely and eventually impossible under realistic electric-field magnitudes. Here we show that such frozen ferroelectric domain walls recover their mobility under the influence of quantum fluctuations. Nonlinear permittivity and polarization-retention measurements of an organic charge-transfer complex reveal that ferroelectric domain-wall creep occurs via an athermal process when the system is tuned close to a pressure-driven ferroelectric quantum critical point. Despite the heavy masses of material building blocks such as molecules, the estimated effective mass of the domain wall is comparable to the proton mass, indicating the realization of a ferroelectric domain wall with a quantum-particle nature near the quantum critical point.
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.
authors.forename: Fumitaka
authors.identifier: http://orcid.org/0000-0002-1763-6799
authors.initials: F
authors.lastname: Kagawa
authors.affiliation: Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Nao
authors.initials: N
authors.lastname: Minami
authors.affiliation: National Institute of Advanced Industrial Science and Technology (AIST), AIST Tsukuba Central 5, 1-1-1 Higashi, Tsukuba 305-8565, Japan.
authors.forename: Sachio
authors.initials: S
authors.lastname: Horiuchi
authors.affiliation: RIKEN Center for Emergent Matter Science (CEMS), Wako 351-0198, Japan.|Department of Applied Physics, The University of Tokyo, Tokyo 113-8656, Japan.
authors.forename: Yoshinori
authors.initials: Y
authors.lastname: Tokura