title: Valley susceptibility of an interacting two-dimensional electron system.
abstract: We report direct measurements of the valley susceptibility, the change of valley population in response to an applied symmetry-breaking strain, in an AlAs two-dimensional electron system. As the two-dimensional density is reduced, the valley susceptibility dramatically increases relative to its band value, reflecting the system's strong electron-electron interaction. The increase has a remarkable resemblance to the enhancement of the spin susceptibility and establishes the analogy between the spin and valley degrees of freedom.
authors.affiliation: Department of Electrical Engineering, Princeton University, Princeton, New Jersey 08544, USA.
authors.forename: O
authors.initials: O
authors.lastname: Gunawan
authors.forename: Y P
authors.initials: YP
authors.lastname: Shkolnikov
authors.forename: K
authors.initials: K
authors.lastname: Vakili
authors.forename: T
authors.initials: T
authors.lastname: Gokmen
authors.forename: E P
authors.initials: EP
authors.lastname: De Poortere
authors.forename: M
authors.initials: M
authors.lastname: Shayegan