Quantum Information -- Theory and Implementation


portrait Géza Giedke
Ikerbasque Research Professor

Donostia International Physics Center
Paseo Manuel de Lardizabal, 4
E-20018 Donostia-San Sebastián, Spain
Tel.: +34 943 018 289    Fax: +34 943 015 600
email: geza.giedke AT dipc DOT org
PGP Public Key 0x91171A19

Online profiles: Research lines:

Research highlights and news

  • January 2024 - Research paper published in Physical Review Letters
    Indistinguishability of identical bosons from a quantum information theory perspective M. Englbrecht; T. Kraft; C. Dittel; A. Buchleitner; G. Giedke & B. Kraus
    Phys. Rev. Lett., 132, 050201 (2024); also available at arXiv:2307.06626.

  • New group member - On October 1st, Andoni Agirre joined our group at DIPC as a PhD student (jointly supervised withTobias Grass and Thomas Frederiksen). He will work on tensor-network methods applied to nanographenes .

  • New group member - On Aug 16th, Lorenz Möhrle from the University of Konstanz joined our group at DIPC as a summer intern. He will work on a project concerning hyperfine interaction in nanographenes (until October).

  • July 2023 Research project granted
    The project proposal PIBA_2023_1_0021 (Tensor network methods for interacting electrons in quasi-1d graphene nanostructures (TENINT)), jointly led with Tobias Grass and Thomas Frederiksen has been granted by the Department of Education of the Basque Government. The project will run for two years.

  • July 2023 - Research visit by Alejandro González-Tudela (Instituto de Física Fundamental (IFF), CSIC, Madrid) (topological photonics)

  • Nico Leumer joined our group from The University of Strasbourg to work on spin dynamics in nanographenes as part of the IKUR project ``Quantum register based on molecular spins and graphene nanostructures''

  • June 30, 2023 - Research paper published in Physical Review B
    Hyperfine interactions in open-shell planar sp2-carbon nanostructures Sanghita Sengupta, Thomas Frederiksen, and Géza Giedke
    Phys. Rev. B 107, 224433 (2023); also available at arXiv:2303.11422.

  • June 19 - July 7, 2023 - Quantum Information Workshop, Benasque (slides of the Future of Quantum Information session)

  • June 15, 2023 - Research paper published in Journal of Physics: Condensed Matter
    Mach-Zehnder-like interferometry with graphene nanoribbon networks Sofia Sanz, Nick Papior, Géza Giedke, Daniel Sánchez-Portal, Mads Brandbyge and Thomas Frederiksen
    J. Phys.: Cond. Mat. 35, 374001 (2023); also available at arXiv:2302.04821.

  • March 27, 2023 - Research paper published in Physical Review B
    Magnetic frustration and fractionalization in oligo(indenoindenes)
    R. Ortiz, G. Giedke, and T. Frederiksen
    Phys. Rev. B 107, L100416 (2023); also available at arXiv:2211.07385.

  • October 7, 2022 - DIPC - UPV/EHU (Donostia - Bilbao) Quantum Workshop 2022 at DIPC

  • August 30 - September 2, 2022 - Summerschool Nanotechnology meets Quantum Information 2022 (NanoQI'22) held in San Sebastián
  • August 2022 - Research visit by Alejandro González-Tudela (Instituto de Física Fundamental (IFF), CSIC, Madrid) (topological photonics)

  • July 15th, 2022 - Research paper published in Physical Review Research
    Long-range electron-electron interactions in quantum dot systems and applications in quantum chemistry
    J. Knörzer, C. J. van Diepen, T.-K. Hsiao, G. Giedke, U. Mukhopadhyay, C. Reichl, W. Wegscheider, J. I. Cirac, and L. M. K. Vandersypen
    Phys. Rev. Research 4, 033043 (2022); also available at arXiv:2202.06756.

  • July 11th, 2022 - Research paper published in Physical Review Letters
    A spin-polarizing electron beam splitter from crossed graphene nanoribbons
    S. Sanz, N. Papior, G. Giedke, D. Sánchez-Portal, M. Brandbyge and T. Frederiksen
    Phys. Rev. Lett. 129, 037701 (2022); also available at arXiv:2201.07147.

  • July 6th, 2022 - Research paper published in Physical Review Applied
    Entangling nuclear spins in distant quantum dots via an electron bus
    M. Bello, M. Benito, M. J. A. Schuetz, G. Platero and G. Giedke
    Phys. Rev. Applied 18, 014009 (2022); also available at arXiv:2012.09507.

  • June 10th, 2022 - Research paper published in Journal of Physics: Condensed Matter
    Energy density as a probe of band representations in photonic crystals
    M. Blanco de Paz, M. A. J. Herrera, P. Arroyo Huidobro, H. Alaeian, M. G. Vergniory, B. Bradlyn, G. Giedke, A. García-Etxarri and D. Bercioux
    J. Phys.: Cond. Mat. 34, 314002 (2022); also available at arXiv:2203.10908.

  • July 19th, 2021 - Research visit by Matthias Englbrecht (Universität Innsbruck) [until October; joint work with Barabara Kraus on the characterization of quantum light sources]

  • Feb 11th, 2021 - Research paper published in Quantum Science and Technology
    Frequency-resolved photon correlations in cavity optomechanics
    M.K. Schmidt, R. Esteban, G. Giedke, J. Aizpurua, and A. Gonzalez-Tudela
    Quant. Sci. Tech. , (2021); also available at arXiv:2009.06216.

  • Jan 11th, 2021 - Research paper published in Phys. Rev. A
    Limit Cycle Phase and Goldstone Mode in Driven Dissipative Systems
    H. Alaeian, G. Giedke, I. Carusotto, R. Löw, and T. Pfau
    Phys. Rev. A 103, 013712 (2021); also available at arXiv:2007.10680.

  • Dec 15th, 2020 - Research paper published in New Journal of Physics
    Symmetry-protection of multiphoton states of light
    J. Lasa-Alonso; M. Molezuelas; J. J. M. Varga; A. García-Etxarri; G. Giedke & G. Molina-Terriza
    New J. Phys. 22, 123010 (2020); also available at arXiv:2007.06942.

  • Oct 13-16th, 2020 Workshop Quantum Thermodynamics of Non-equilibrium Systems

  • Jul 24th, 2020 - Research paper published in Phys Rev B
    Crossed graphene nanoribbons as beam splitters and mirrors for electron quantum optics
    S. Sanz, P. Brandimarte; G. Giedke; D. Sánchez-Portal & T. Frederiksen
    Phys. Rev. B 102, 035436 (2020); also available at arXiv:2005.11391.

  • Jul 20-24th, 2020 visit at MPQ Garching

  • May 18th, 2020 - Research paper published in Phys Rev A
    Teleporting Quantum Information Encoded in Fermionic Modes
    T. Debarba, F. Iemini, G. Giedke, and N. Friis
    Phys. Rev. A 101, 052326 (2020); also available at arXiv:2002.08201.

  • Mar 3rd, 2020 - Research paper published in Phys Rev B
    Wigner crystals in two-dimensional transition-metal dichalcogenides: Spin physics and readout
    J. Knörzer, M. J. A. Schuetz, G. Giedke, D. S. Wild, K. De Greve, R. Schmidt, M. D. Lukin, and J. I. Cirac
    Phys. Rev. B 101, 125101 (2020); also available at arXiv:1912.11089.

    We propose and analyze a high-fidelity hot gate for generic spin-resonator systems which allows for coherent spin-spin coupling, in the presence of a thermally populated resonator mode. Our scheme is nonperturbative in the spin-resonator coupling strength, applies to a broad class of physical systems, including, for example, spins coupled to circuit-QED and surface acoustic wave resonators as well as nanomechanical oscillators, and can be implemented readily with state-of-the-art experimental setups. We provide and numerically verify simple expressions for the fidelity of creating maximally entangled states under realistic conditions.

  • New group member - In April 2017, Maria Blanco de Paz joined the project SOPhoQua (run jointly with Dario Bercioux, Aitzol Garcia-Etxarri, and Juan José Saenz) as a PhD student.

  • February 2017 Red de Información y Tecnologias Cuánticas (FIS2016-81891-REDT) led by Juanjo García-Ripoll (CSIC-IFF) has been approved by MINECO

  • Summerschool NanoQI'17 - The summerschool Nanotechnology meets Quantum Information jointly organized by DIPC and MPQ will take place from Jul 24th to 28th and is now open for applications until April 28th.

  • Januar 2017 - Project "Spin-orbit Photonics and Quantum Applications" (PI_2016_1_0041; jointly with Dario Bercioux, Aitzol Garcia-Etxarri, and Juanjo Saenz)

  • November 2016 two new free/open journals on quantum physics with interesting publishing philosophy and refereeing model have been founded: the arXiv-overlay journal Quantum and the "peer-witnessed refereeing" journal SciPost . Good luck to these endeavours!

  • Sep 1st, 2016 - Research paper published in Phys Rev B
    Dissipative Long-Range Entanglement Generation between Electronic Spins
    M. Benito, M.J.A. Schuetz, J.I. Cirac, G. Platero, & G. Giedke
    Phys. Rev. B 94, 115404 (2016).

    We propose a scheme for deterministic generation and long-term stabilization of entanglement between two electronic spin qubits confined in spatially separated quantum dots. Our approach relies on an electronic quantum bus, consisting either of quantum Hall edge channels or surface acoustic waves, that can mediate long-range coupling between localized spins over distances of tens of micrometers. Since the entanglement is actively stabilized by dissipative dynamics, our scheme is inherently robust against noise and imperfections.

  • May 20th, 2016 - Research paper published in ACS Nano
    Quantum Mechanical Description of Raman Scattering from Molecules in Plasmonic Cavities, ACS Nano Article ASAP (2016)
    by M.K.S. Schmidt, R. Esteban, A. González-Tudela, G. Giedke, and J. Aizpurua

    Plasmon-enhanced Raman scattering can push single-molecule vibrational spectroscopy beyond a regime addressable by classical electrodynamics. We employ a quantum electrodynamics (QED) description of the coherent interaction of plasmons and molecular vibrations that reveal the emergence of nonlinearities in the inelastic response of the system. For realistic situations, we predict the onset of phonon-stimulated Raman scattering and a counterintuitive dependence of the anti-Stokes emission on the frequency of excitation. We further show that this QED framework opens a venue to analyze the correlations of photons emitted from a plasmonic cavity.

  • Summerschool - From July 11-14, 2016 the summerschool Nanotechnology meets Quantum Information (NanoQI) jointly organized by DIPC and MPQ will take place. Registration deadline is April 30th.

  • June 14, 2016 : 1st Basque Quantum Science and Technology Workshop at Nanogune, San Sebastian

  • Support the Quantum Manifesto! calling upon Member States and the European Commission to launch a EUR 1 billion Flagship-scale Initiative in Quantum Technology.

  • New group member - In Jan 2016, Dr Omjyoti Dutta joined our group at DIPC as a postdoctoral researcher. He will work on quantum simulations and engineering with cold atoms and polar molecules.

  • September 10th, 2015 - Research paper published in Physical Review X
    Universal Quantum Transducers Based on Surface Acoustic Waves, Phys. Rev. X 5 031031 (2015)
    by M.J.A. Schuetz, E.M. Kessler, G. Giedke, L.M.K. Vandersypen, M.D. Lukin, and J.I. Cirac

    We propose a universal, on-chip quantum transducer based on surface acoustic waves in piezoactive materials. Because of the intrinsic piezoelectric (and/or magnetostrictive) properties of the material, our approach provides a universal platform capable of coherently linking a broad array of qubits, including quantum dots, trapped ions, nitrogen-vacancy centers, or superconducting qubits. The quantized modes of surface acoustic waves lie in the gigahertz range and can be strongly confined close to the surface in phononic cavities and guided in acoustic waveguides. We show that this type of surface acoustic excitation can be utilized efficiently as a quantum bus, serving as an on-chip, mechanical cavity-QED equivalent of microwave photons and enabling long-range coupling of a wide range of qubits.
    See also this highlight in Physics.