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Related papers: Coupled quantum dots as quantum gates

200 papers

We report the observation of an unusually large number of consecutive spin pairs in a weakly coupled many-electron GaAs/AlGaAs quantum dot. The pairs are identified due to pairwise parallel shifts of Coulomb resonances in a perpendicular…

Mesoscale and Nanoscale Physics · Physics 2015-09-29 S. Hellmüller , D. Bischoff , T. Müller , M. Beck , K. Ensslin , T. Ihn

The effects of spin-orbit (SO) coupling arising from the confinement potential in single and two vertically-coupled quantum dots have been investigated. Our work indicates that a dot containing a single electron shows the lifting of the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Anjana Bagga , Pekka Pietilainen , Tapash Chakraborty

We present excitation energy spectra of few-electron vertically coupled quantum dots for strong and intermediate inter-dot coupling. By applying a magnetic field, we induce ground state transitions and identify the corresponding quantum…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 M. Rontani , S. Amaha , K. Muraki , F. Manghi , E. Molinari , S. Tarucha , D. G. Austing

Quasi-static transport measurements are employed to characterize a few electron quantum dot electrostatically defined in a GaAs/AlGaAs heterostructure. The gate geometry allows observations on one and the same electron droplet within a wide…

Mesoscale and Nanoscale Physics · Physics 2009-08-19 A. K. Huettel , K. Eberl , S. Ludwig

We have investigated the dynamics of the electron-nuclei coupled system in quantum dots. The bunching of results of the electron spin measurements and the revival in the conditional probabilities are salient features of the nuclear spin…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Ozgur Cakir , Toshihide Takagahara

We study a system of two symmetrical capacitively coupled quantum dots, each coupled to its own metallic lead, focusing on its evolution as a function of the gate voltage applied to each dot. Using the numerical renormalization group and…

Strongly Correlated Electrons · Physics 2007-05-23 Andrew K. Mitchell , Martin R. Galpin , David E. Logan

In order to understand the orbital and spin magnetization of a confined electronic system we analyze these ground state properties in the transition from a quantum dot to a quantum ring of finite thickness. The Coulomb interaction between…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Gabriel Vasile , Vidar Gudmundsson , Andrei Manolescu

Motivated by recent experiments of Zajac et al. [arXiv:1708.03530], we theoretically describe high-fidelity two-qubit gates using the exchange interaction between the spins in neighboring quantum dots subject to a magnetic field gradient.…

Mesoscale and Nanoscale Physics · Physics 2018-02-22 Maximilian Russ , D. M. Zajac , A. J. Sigillito , F. Borjans , J. M. Taylor , J. R. Petta , Guido Burkard

The creation, coherent manipulation, and measurement of spins in nanostructures open up completely new possibilities for electronics and information processing, among them quantum computing and quantum communication. We review our…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 P. Recher , D. Loss , J. Levy

The physics of quantum dots is succinctly depicted by the {\it Universal Hamiltonian}, where only zero mode interactions are included. In the case where the latter involve charging and isotropic spin-exchange terms, this would lead to a…

Mesoscale and Nanoscale Physics · Physics 2011-08-29 Boaz Nissan-Cohen , Yuval Gefen , Mikhail N. Kiselev , Igor V. Lerner

We investigate the dynamics of two interacting electrons confined to a pair of coupled quantum dots driven by an external AC field. By numerically integrating the two-electron Schroedinger equation in time, we find that for certain values…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 C. E. Creffield , G. Platero

We show how to eliminate the first-order effects of the spin-orbit interaction in the performance of a two-qubit quantum gate. Our procedure involves tailoring the time dependence of the coupling between neighboring spins. We derive an…

Quantum Physics · Physics 2009-11-07 N. E. Bonesteel , D. Stepanenko , D. P. DiVincenzo

We study the electric and thermoelectric transport properties of correlated quantum dots coupled to two ferromagnetic leads and one superconducting electrode. Transport through such hybrid devices depends on the interplay of…

Mesoscale and Nanoscale Physics · Physics 2015-06-19 Krzysztof P. Wojcik , Ireneusz Weymann

We investigate two equivalent, capacitively coupled semiconducting quantum dots, each coupled to its own lead, in a regime where there are two electrons on the double dot. With increasing interdot coupling a rich range of behavior is…

Strongly Correlated Electrons · Physics 2007-05-23 Martin R. Galpin , David E. Logan , H. R. Krishnamurthy

We study the effect of spin-orbit coupling on quantum gates produced by pulsing the exchange interaction between two single electron quantum dots. Spin-orbit coupling enters as a small spin precession when electrons tunnel between dots. For…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 D. Stepanenko , N. E. Bonesteel , D. P. DiVincenzo , G. Burkard , Daniel Loss

We investigate the transport properties of a quantum dot coupled to leads interacting with a multi-spin system using the generalized master equation within the Coulomb blockade regime. We find that if two states for each scattering region…

Mesoscale and Nanoscale Physics · Physics 2025-12-30 Eric D. Switzer , Xiao-Guang Zhang , Volodymyr Turkowski , Talat S. Rahman

We demonstrate double quantum dots fabricated in undoped Si/SiGe heterostructures relying on a double top-gated design. Charge sensing shows that we can reliably deplete these devices to zero charge occupancy. Measurements and simulations…

We study a double quantum dot each dot of which is tunnel-coupled to superconducting leads. In the Coulomb blockade regime, a spin-dependent Josephson coupling between two superconductors is induced, as well as an antiferromagnetic…

Mesoscale and Nanoscale Physics · Physics 2009-10-31 Mahn-Soo Choi , C. Bruder , Daniel Loss

We report coherent operation of a singlet-triplet qubit controlled by the arrangement of two electrons in an adjacent double quantum dot. The system we investigate consists of two pairs of capacitively coupled double quantum dots fabricated…

Mesoscale and Nanoscale Physics · Physics 2011-07-20 I. van Weperen , B. D. Armstrong , E. A. Laird , J. Medford , C. M. Marcus , M. P. Hanson , A. C. Gossard

We set up and parametrize a Hubbard model for interacting quantum dots in bilayer graphene and study double dots as the smallest multi-dot system. We demonstrate the tunability of the spin and valley multiplets, Hubbard parameters, and…

Mesoscale and Nanoscale Physics · Physics 2024-09-02 Angelika Knothe , Guido Burkard