title: Dispersively Detected Pauli Spin-Blockade in a Silicon Nanowire Field-Effect Transistor.
abstract: We report the dispersive readout of the spin state of a double quantum dot formed at the corner states of a silicon nanowire field-effect transistor. Two face-to-face top-gate electrodes allow us to independently tune the charge occupation of the quantum dot system down to the few-electron limit. We measure the charge stability of the double quantum dot in DC transport as well as dispersively via in situ gate-based radio frequency reflectometry, where one top-gate electrode is connected to a resonator. The latter removes the need for external charge sensors in quantum computing architectures and provides a compact way to readout the dispersive shift caused by changes in the quantum capacitance during inter-dot charge transitions. Here, we observe Pauli spin-blockade in the high-frequency response of the circuit at finite magnetic fields between singlet and triplet states. The blockade is lifted at higher magnetic fields when intra-dot triplet states become the ground state configuration. A line shape analysis of the dispersive phase shift reveals furthermore an intra-dot valley-orbit splitting Δvo of 145 μeV. Our results open up the possibility to operate compact complementary metal-oxide semiconductor (CMOS) technology as a singlet-triplet qubit and make split-gate silicon nanowire architectures an ideal candidate for the study of spin dynamics.
authors.affiliation: †Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: A C
authors.initials: AC
authors.lastname: Betz
authors.affiliation: ‡CEA/LETI-MINATEC, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble, France.
authors.forename: R
authors.initials: R
authors.lastname: Wacquez
authors.affiliation: ‡CEA/LETI-MINATEC, CEA-Grenoble, 17 rue des Martyrs, F-38054 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Vinet
authors.affiliation: §SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, 38054 Grenoble, France.
authors.forename: X
authors.initials: X
authors.lastname: Jehl
authors.affiliation: ∥Instituto de Fisica, Universidade Federal do Rio de Janeiro, Caixa Postal 68528, 21941-972 Rio de Janeiro, Brazil.
authors.forename: A L
authors.initials: AL
authors.lastname: Saraiva
authors.affiliation: §SPSMS, UMR-E CEA/UJF-Grenoble 1, INAC, 17 rue des Martyrs, 38054 Grenoble, France.
authors.forename: M
authors.initials: M
authors.lastname: Sanquer
authors.affiliation: ⊥Cavendish Laboratory, University of Cambridge, Cambridge CB3 0HE, United Kingdom.
authors.forename: A J
authors.initials: AJ
authors.lastname: Ferguson
authors.affiliation: †Hitachi Cambridge Laboratory, J. J. Thomson Avenue, Cambridge CB3 0HE, United Kingdom.
authors.forename: M F
authors.initials: MF
authors.lastname: Gonzalez-Zalba
keywords: Double quantum dot; Pauli spin-blockade; dispersive radio frequency readout; silicon