Silicon/Germanium spin qubits have attracted increasing attention and have made outstanding progress in the past few years. In these devices, the elementary information is stored as a coherent superposition of the spin states of an electron in a Si/SiGe heterostructure, or of a hole in a Ge/SiGe heterostructure. These spins can be manipulated electrically owing to the intrinsic (or to a synthetic) spin-orbit coupling, and get entangled through exchange interactions, allowing for the implementation of a variety of one- and two-qubit gates required for quantum computing and simulation. Si/Ge heterostructures hold various records in semiconductor spin qubit technologies [1, 2], as they provide very clean epitaxial interfaces, and can be made free of nuclear spins that would interfere with the electron or hole spins.
It is essential to support the development of these advanced quantum technologies with state-of-the-art theory and modeling. For that purpose, CEA/IRIG is actively developing the “TB_Sim” code. TB_Sim is able to describe very realistic qubit structures down to the atomic scale if needed using atomistic tight-binding and multi-bands k.p models for the electronic structure of the materials. Using TB_Sim, CEA has made significant progress in the understanding of various aspects of the physics of spin qubits (spin-orbit interactions, valley splittings…), in tight collaboration with the experimental groups in Grenoble and with the partners of CEA in Europe [3-11].
The present position is open in the context of the European project “SPINS”, which aims at developing pilot lines for spin qubit technologies.
Objectives of this position:
The aims of this position are to strengthen our understanding and support the development of electron and hole spin qubit devices based on Si/Ge heterostructures through analytical modeling as well as advanced numerical simulation with TB_Sim. Topics of interests include:
- Structural and electronic properties of Si/SiGe and Ge/SiGe dots (strain inhomogeneities, valley splittings, …)
- Spin manipulation & readout in electron and hole spin qubits (intrinsic & synthetic spin-orbit fields),
- Exchange interactions in 1D and 2D arrays of spin qubits,
- Sensitivity to noise (decoherence) and disorder (variability),
- Shuttling (transport of spins).
The selected candidate will join a lively project bringing together > 40 people with comprehensive expertise covering the design, fabrication, characterization and modeling of spin qubits, as well as related disciplines (cryo-electronics, quantum algorithms and quantum error correction, ...). He/She will have the opportunity to interact with the partners of the SPINS project in Europe (Delft, IMEC, …).
How to apply ?
The candidate should send his/her CV to Yann-Michel Niquet (yniquet@cea.fr), with a list of publications, a motivation letter with a summary of past accomplishments, and arrange for two recommendation letters. The position is open until filled.
Required qualifications: The candidate must have a PhD in Quantum, Condensed Matter or Solid-State Physics (or related topics).
The pdf of this announcement is available at: https://ymniquet.fr/documents/Postdoc.pdf
References:
[1] Universal control of a six-qubit quantum processor in silicon,
S. G. J. Philips, M. T. Mądzik, S. V. Amitonov, S. L. de Snoo, M. Russ, N. Kalhor, C. Volk, W. I. L. Lawrie, D. Brousse, L. Tryputen, B. Paquelet Wuetz, A. Sammak, M. Veldhorst, G. Scappucci, and L. M. K. Vandersypen, Nature 609, 919 (2022).
[2] Robust and localised control of a 10-spin qubit array in germanium,
V. John, C. X. Yu, B. van Straaten, E. A. Rodríguez-Mena, M. Rodríguez, S. D. Oosterhout, L. E. A. Stehouwer, G. Scappucci, M. Rimbach-Russ, S. Bosco, F. Borsoi, Y.-M. Niquet and M. Veldhorst, Nature Communications 16, 10560 (2025).
[3] Electrically driven electron spin resonance mediated by spin–valley–orbit coupling in a silicon quantum dot,
A. Corna, L. Bourdet, R. Maurand, A. Crippa, D. Kotekar-Patil, H. Bohuslavskyi, R. Laviéville, L. Hutin, S. Barraud, X. Jehl, M. Vinet, S. de Franceschi, Y.-M. Niquet and M. Sanquer, npj Quantum Information 4, 6 (2018).
[4] A single hole spin with enhanced coherence in natural silicon,
N. Piot, B. Brun, V. Schmitt, S. Zihlmann, V. P. Michal, A. Apra, J. C. Abadillo-Uriel, X. Jehl, B. Bertrand, H. Niebojewski, L. Hutin, M. Vinet, M. Urdampilleta, T. Meunier, Y.-M. Niquet, R. Maurand and S. De Franceschi, Nature Nanotechnology 17, 1072 (2022).
[5] Strong coupling between a photon and a hole spin in silicon,
C. X. Yu, S. Zihlmann, J.- C. Abadillo-Uriel, V. P. Michal, N. Rambal, H. Niebojewski, T. Bedecarrats, M. Vinet, E. Dumur, M. Filippone, B. Bertrand, S. De Franceschi, Y.-M. Niquet and R. Maurand, Nature Nanotechnology 18, 741 (2023).
[6] Optimal operation of hole spin qubits,
M. Bassi, E. A. Rodríguez-Mena, B. Brun, S. Zihlmann, T. Nguyen, V. Champain, J. C. Abadillo-Uriel, B. Bertrand, H. Niebojewski, R. Maurand, Y.-M. Niquet, X. Jehl, S. De Franceschi and V. Schmitt, Nature Physics 22, 75 (2026).
[7] Electrical manipulation of semiconductor spin qubits within the g-matrix formalism,
B. Venitucci, L. Bourdet, D. Pouzada and Y.-M. Niquet, Physical Review B 98, 155319 (2018).
[8] Hole spin manipulation in inhomogeneous and non-separable electric fields,
B. Martinez, J.-C. Abadillo-Uriel, E. A. Rodríguez -Mena and Y.-M. Niquet, Physical Review B 106, 235426 (2022).
[9] Hole-spin driving by strain-induced spin-orbit interactions,
J.-C. Abadillo-Uriel, E. A. Rodríguez-Mena, B. Martinez and Y.-M. Niquet, Physical Review Letters 131, 097002 (2023).
[10] Variability of hole-spin qubits in planar germanium,
B. Martinez and Y.-M. Niquet, Physical Review Applied 25, 014018 (2026) [Editor’s suggestion].
[11] Valley physics in the two-band k.p model for SiGe heterostructures and spin qubits,
T. Salamone, B. Martinez Diaz, J. Li, L. Cvitkovich and Y.-M. Niquet, Physical Review B 113, 115304 (2026) [Editor’s suggestion].
Additional informations about the laboratory:
http://www.cea.fr/drf/irig/english/Pages/Departments/DPhy.aspx
http://www.researchgate.net/profile/Yann-Michel_Niquet
http://scholar.google.fr/citations?user=h02ymwoAAAAJ
The group responsible for spin qubits modeling now includes two permanent researchers (Y.-M. Niquet, M. Filippone), two PhD students and two postdocs.
More about Grenoble and its surroundings:
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