José Carlos Abadillo-Uriel

Recent publications and preprints

1. 

   Linear-in-momentum spin orbit interactions in planar Ge/GeSi heterostructures and spin qubits

   Esteban A. Rodríguez-Mena, Jose Carlos Abadillo-Uriel, Gaëtan Veste, Biel Martinez, Jing Li, Benoît Sklénard, and 1 more author

   arXiv preprint arXiv:2212.03691, Jul 2023

   Abs arXiv Bib URL

   We investigate the existence of linear-in-momentum spin-orbit interactions in the valence band of Ge/GeSi heterostructures using an atomistic tight-binding method. We show that symmetry breaking at the Ge/GeSi interfaces gives rise to a linear Dresselhaus-type interaction for heavy-holes. This interaction results from the heavy-hole/light-hole mixings induced by the interfaces and can be captured by a suitable correction to the minimal Luttinger-Kohn, four bands k.p Hamiltonian. It is dependent on the steepness of the Ge/GeSi interfaces, and is suppressed if interdiffusion is strong enough. Besides the Dresselhaus interaction, the Ge/GeSi interfaces also make a contribution to the in-plane gyromagnetic g-factors of the holes. The tight-binding calculations also highlight the existence of a small linear Rashba interaction resulting from the couplings between the heavy-hole/light-hole manifold and the conduction band enabled by the low structural symmetry of Ge/GeSi heterostructures. These interactions can be leveraged to drive the hole spin. The linear Dresselhaus interaction may, in particular, dominate the physics of the devices for out-of-plane magnetic fields. When the magnetic field lies in-plane, it is, however, usually far less efficient than the g-tensor modulation mechanisms arising from the motion of the dot in non-separable, inhomogeneous electric fields and strains.

   @article{rodríguez2023linear,
     title = {Linear-in-momentum spin orbit interactions in planar Ge/GeSi heterostructures and spin qubits},
     author = {Rodríguez-Mena, Esteban A. and Abadillo-Uriel, Jose Carlos and Veste, Gaëtan and Martinez, Biel and Li, Jing and Sklénard, Benoît and Niquet, Yann-Michel},
     journal = {arXiv preprint arXiv:2212.03691},
     year = {2023},
     month = jul,
     doi = {https://doi.org/10.48550/arXiv.2307.10007}
   }

2. 

   Strong coupling between a photon and a hole spin in silicon

   Cecile X Yu, Simon Zihlmann, Jose C Abadillo-Uriel, Vincent P Michal, Nils Rambal, Heimanu Niebojewski, and 5 more authors

   Nature Nanotechnology, Mar 2023

   Abs arXiv Bib URL

   Spins in semiconductor quantum dots constitute a promising platform for scalable quantum information processing. Coupling them strongly to the photonic modes of superconducting microwave resonators would enable fast non-demolition readout and long-range, on-chip connectivity, well beyond nearest-neighbor quantum interactions. Here we demonstrate strong coupling between a microwave photon in a superconducting resonator and a hole spin in a silicon-based double quantum dot issued from a foundry-compatible MOS fabrication process. By leveraging the strong spin-orbit interaction intrinsically present in the valence band of silicon, we achieve a spin-photon coupling rate as high as 330 MHz largely exceeding the combined spin-photon decoherence rate. This result, together with the recently demonstrated long coherence of hole spins in silicon, opens a new realistic pathway to the development of circuit quantum electrodynamics with spins in semiconductor quantum dots.

   @article{yu2022strong,
     title = {Strong coupling between a photon and a hole spin in silicon},
     author = {Yu, Cecile X and Zihlmann, Simon and Abadillo-Uriel, Jose C and Michal, Vincent P and Rambal, Nils and Niebojewski, Heimanu and Bedecarrats, Thomas and Vinet, Maud and Dumur, Etienne and Filippone, Michele and others},
     journal = {Nature Nanotechnology},
     pages = {1--6},
     year = {2023},
     month = mar,
     publisher = {Nature Publishing Group UK London},
     url = {https://www.nature.com/articles/s41565-023-01332-3},
     doi = {10.1038/s41565-023-01332-3}
   }

3. 

   Tunable hole spin-photon interaction based on g-matrix modulation

   V. P. Michal, J. C. Abadillo-Uriel, S. Zihlmann, R. Maurand, Y.-M. Niquet, and M. Filippone

   Phys. Rev. B, Jan 2023

   Abs arXiv Bib URL

   We consider a spin circuit-QED device where a superconducting microwave resonator is capacitively coupled to a single hole confined in a semiconductor quantum dot. Thanks to the strong spin-orbit coupling intrinsic to valence-band states, the gyromagnetic g-matrix of the hole can be modulated electrically. This modulation couples the photons in the resonator to the hole spin. We show that the applied gate voltages and the magnetic-field orientation enable a versatile control of the spin-photon interaction, whose character can be switched from fully transverse to fully longitudinal. The longitudinal coupling is actually maximal when the transverse one vanishes and vice-versa. This "reciprocal sweetness" results from geometrical properties of the g-matrix and protects the spin against dephasing or relaxation. We estimate coupling rates reaching   10 MHz in realistic settings and discuss potential circuit-QED applications harnessing either the transverse or the longitudinal spin-photon interaction. Furthermore, we demonstrate that the g-matrix curvature can be used to achieve parametric longitudinal coupling with enhanced coherence.

   @article{michal2022tunable,
     title = {Tunable hole spin-photon interaction based on g-matrix modulation},
     author = {Michal, V. P. and Abadillo-Uriel, J. C. and Zihlmann, S. and Maurand, R. and Niquet, Y.-M. and Filippone, M.},
     journal = {Phys. Rev. B},
     volume = {107},
     issue = {4},
     pages = {L041303},
     numpages = {6},
     year = {2023},
     month = jan,
     publisher = {American Physical Society},
     doi = {10.1103/PhysRevB.107.L041303},
     url = {https://link.aps.org/doi/10.1103/PhysRevB.107.L041303},
   }

4. 

   Hole spin manipulation in inhomogeneous and nonseparable electric fields

   Biel Martinez, Jose Carlos Abadillo-Uriel, Esteban A. Rodrı́guez-Mena, and Yann-Michel Niquet

   Phys. Rev. B, Dec 2022

   Abs arXiv Bib URL VIDEO

   The usual models for electrical spin manipulation in semiconductor quantum dots assume that the confinement potential is separable in the three spatial dimensions and that the ac drive field is homogeneous. However, the electric field induced by the gates in quantum dot devices is not fully separable and displays significant inhomogeneities. Here we address the electrical manipulation of hole spins in semiconductor heterostructures subject to inhomogeneous vertical electric fields and/or in-plane ac electric fields. We consider Ge quantum dots electrically confined in a Ge/GeSi quantum well as an illustration. We show that the lack of separability between the vertical and in-plane motions gives rise to an additional spin-orbit coupling mechanism (beyond the usual linear and cubic in momentum Rashba terms) that modulates the principal axes of the hole gyromagnetic g matrix. This nonseparability mechanism can be of the same order of magnitude as Rashba-type interactions, and enables spin manipulation when the magnetic field is applied in the plane of the heterostructure even if the dot is symmetric (disk shaped). More generally, we show that Rabi oscillations in strongly patterned electric fields harness a variety of g-factor modulations. We discuss the implications for the design, modeling, and understanding of hole spin qubit devices.

   @article{PhysRevB.106.235426,
     title = {Hole spin manipulation in inhomogeneous and nonseparable electric fields},
     author = {Martinez, Biel and Abadillo-Uriel, Jose Carlos and Rodr\'{\i}guez-Mena, Esteban A. and Niquet, Yann-Michel},
     journal = {Phys. Rev. B},
     volume = {106},
     issue = {23},
     pages = {235426},
     numpages = {12},
     year = {2022},
     month = dec,
     publisher = {American Physical Society},
     doi = {10.1103/PhysRevB.106.235426},
     url = {https://link.aps.org/doi/10.1103/PhysRevB.106.235426},
     video = {https://www.youtube.com/watch?v=rPtZJ5Mt6V8}
   }

5. 

   Hole spin driving by strain-induced spin-orbit interactions

   Jose Carlos Abadillo-Uriel, Esteban A Rodrı́guez-Mena, Biel Martinez, and Yann-Michel Niquet

   arXiv preprint arXiv:2212.03691, Dec 2022

   Abs arXiv Bib

   Hole spins in semiconductor quantum dots can be efficiently manipulated with radio-frequency electric fields owing to the strong spin-orbit interactions in the valence bands. Here we show that the motion of the dot in inhomogeneous strain fields gives rise to linear Rashba spin-orbit interactions (with spatially dependent spin-orbit lengths) and g-factor modulations that allow for fast Rabi oscillations. Such inhomogeneous strains may build up spontaneously due to process and cool down stress. We discuss spin qubits in Ge/GeSi heterostructures as an illustration. We highlight that Rabi frequencies can be enhanced by one order of magnitude by shear strain gradients as small as 3x10^-6 nm^-1 within the dots. This underlines that spin in solids can be very sensitive to strains and opens the way for strain engineering in hole spin devices for quantum information and spintronics.

   @article{abadillo2022hole,
     title = {Hole spin driving by strain-induced spin-orbit interactions},
     author = {Abadillo-Uriel, Jose Carlos and Rodr{\'\i}guez-Mena, Esteban A and Martinez, Biel and Niquet, Yann-Michel},
     journal = {arXiv preprint arXiv:2212.03691},
     year = {2022},
   }

6. 

   A single hole spin with enhanced coherence in natural silicon

   N. Piot, B. Brun, V. Schmitt, S. Zihlmann, V. P. Michal, A. Apra, and 11 more authors

   Nature Nanotechnology, Sep 2022

   Abs arXiv Bib URL

   Semiconductor spin qubits based on spin–orbit states are responsive to electric field excitations, allowing for practical, fast and potentially scalable qubit control. Spin electric susceptibility, however, renders these qubits generally vulnerable to electrical noise, which limits their coherence time. Here we report on a spin–orbit qubit consisting of a single hole electrostatically confined in a natural silicon metal-oxide-semiconductor device. By varying the magnetic field orientation, we reveal the existence of operation sweet spots where the impact of charge noise is minimized while preserving an efficient electric-dipole spin control. We correspondingly observe an extension of the Hahn-echo coherence time up to 88 μs, exceeding by an order of magnitude existing values reported for hole spin qubits, and approaching the state-of-the-art for electron spin qubits with synthetic spin–orbit coupling in isotopically purified silicon. Our finding enhances the prospects of silicon-based hole spin qubits for scalable quantum information processing.

   @article{Piot2022,
     doi = {10.1038/s41565-022-01196-z},
     url = {https://doi.org/10.1038/s41565-022-01196-z},
     year = {2022},
     month = sep,
     publisher = {Springer Science and Business Media {LLC}},
     volume = {17},
     number = {10},
     pages = {1072--1077},
     author = {Piot, N. and Brun, B. and Schmitt, V. and Zihlmann, S. and Michal, V. P. and Apra, A. and Abadillo-Uriel, J. C. and Jehl, X. and Bertrand, B. and Niebojewski, H. and Hutin, L. and Vinet, M. and Urdampilleta, M. and Meunier, T. and Niquet, Y.-M. and Maurand, R. and Franceschi, S. De},
     title = {A single hole spin with enhanced coherence in natural silicon},
     journal = {Nature Nanotechnology},
   }