title: Long-distance coherent coupling in a quantum dot array.
abstract: Controlling long-distance quantum correlations is central to quantum computation and simulation. In quantum dot arrays, experiments so far rely on nearest-neighbour couplings only, and inducing long-distance correlations requires sequential local operations. Here, we show that two distant sites can be tunnel-coupled directly. The coupling is mediated by virtual occupation of an intermediate site, with a strength that is controlled via the energy detuning of this site. It permits a single charge to oscillate coherently between the outer sites of a triple dot array without passing through the middle, as demonstrated through the observation of Landau-Zener-Stückelberg interference. The long-distance coupling significantly improves the prospects of fault-tolerant quantum computation using quantum dot arrays, and opens up new avenues for performing quantum simulations in nanoscale devices.
authors.affiliation: Kavli Institute of Nanoscience, TU Delft, 2600 GA Delft, The Netherlands.
authors.forename: F R
authors.initials: FR
authors.lastname: Braakman
authors.forename: P
authors.initials: P
authors.lastname: Barthelemy
authors.forename: C
authors.initials: C
authors.lastname: Reichl
authors.forename: W
authors.initials: W
authors.lastname: Wegscheider
authors.forename: L M K
authors.initials: LM
authors.lastname: Vandersypen
mesh_terms: D039301:Computers, Molecular; D006801:Humans; D049329:Nanostructures; D036103:Nanotechnology / Q000379:methods; D045663:Quantum Dots; D012825:Silicon / Q000737:chemistry*
chemical_list: D012825:Silicon