It is widely believed that next-generation electronic devices will exploit the quantum mechanical nature of electrons, as opposed to the classical operating principles of current electronics. This is one of the leading paradigms at the origin of quantum spintronics, a developing field whose goal is to create useful device functionalities out of the spin degree of freedom of electrons.
So far, quantum spintronics has remained a matter of basic research. In spite of some remarkable progress, a number of hurdles remain to be overcome so that disruptive solutions and radically new approaches are needed.
The “Silicon platform for Quantum Spintronics” (SiSPIN) project brings together a multidisciplinary team of recognised European experts with a strong track record of cooperative work in the field of ultra-sensitive measurements of nanostructures at low temperature and in extreme conditions. SiSPIN Technological implications range from improving the switching performance of classical logic gates (e.g. towards lower energy consumption) up to the implementation of quantum computing devices based on spin qubits.
Matthias Brauns, Joost Ridderbos, Ang Li, Wilfred G. van der Wiel, Erik P. A. M. Bakkers, and Floris A. Zwanenburg, Highly tuneable hole quantum dots in Ge-Si core-shell nanowires, Appl. Phys. Lett. 109, 143113 (October 2016)
Matthias Brauns, Joost Ridderbos, Ang Li, Erik P. A. M. Bakkers, and Floris A. Zwanenburg, Electric-field dependent g-factor anisotropy in Ge-Si core-shell nanowire quantum dots, Phys. Rev. B 93, 121408 (2016)
H. Bohuslavskyi, D. Kotekar-Patil1, R. Maurand, A. Corna, S. Barraud, L. Bourdet, L. Hutin, Y.-M. Niquet, X. Jehl, S. De Franceschi, M. Vinet and M. Sanquer, Pauli blockade in a few-hole PMOS double quantum dot limited by spin-orbit interaction, Appl. Phys. Lett. 109, 193101 (2016)
Edwin Barnes, Mark S. Rudner, Frederico Martins, Filip K. Malinowski, Charles M. Marcus, and Ferdinand Kuemmeth, Filter function formalism beyond pure dephasing and non-Markovian noise in singlet-triplet qubits, Phys. Rev. B 93, 121407 (2016)
Hannes Watzinger, Christoph Kloeffel, Lada Vukušić, Marta D. Rossell, Violetta Sessi, Josip Kukučka, Raimund Kirchschlager, Elisabeth Lausecker, Alisha Truhlar, Martin Glaser, Armando Rastelli, Andreas Fuhrer, Daniel Loss and Georgios Katsaros, Heavy hole states in Germanium hut wires, Accepted in NanoLetters (July 2016)
Matthias Brauns, Joost Ridderbos, Ang Li, Erik P. A. M. Bakkers, Wilfred G. van der Wiel, and Floris A. Zwanenburg, Anisotropic Pauli spin blockade in hole quantum dots, Phys. Rev. B 94, 041411 (R)(July 2016)
Xavier Jehl, Yann-Michel Niquet, and Marc Sanquer, Single donor electronics and quantum functionalities with advanced CMOS technology, Journal of Physics: Condensed Matter, Volume 28, Number 10 (February 2016)
F. Martins, F. K. Malinowski, P. D. Nissen, E. Barnes, S. Fallahi, G. C. Gardner, M. J. Manfra, C. M. Marcus, and F. Kuemmeth, Noise Suppression Using Symmetric Exchange Gates in Spin Qubits, Phys. Rev. Lett. 116, 116801 (2016)
R. Lavieville, F. Triozon, S. Barraud, A. Corna, X. Jehl, M. Sanquer, J. Li, A. Abisset, I. Duchemin, and Y. Niquet, Quantum Dot Made in Metal Oxide Silicon-Nanowire Field Effect Transistor Working at Room Temperature, NANO Letters (2015)
Barraud S., Hartmann J.-M., Maffini-Alvaro V., Tosti L., Delaye V., Lafond D., Top-Down Fabrication of Epitaxial SiGe/Si Multi-(Core/Shell) p-FET Nanowire Transistors, IEEE transactions on electron devices, Vol. 61, No. 4(2014)
Benoit Voisin, Viet-Hung Nguyen, Julien Renard, Xavier Jehl, Sylvain Barraud, François Triozon, Maud Vinet, Ivan Duchemin, Yann-Michel Niquet, Silvano de Franceschi, and Marc Sanquer, Few-Electron Edge-State Quantum Dots in a Silicon Nanowire Field-Effect Transistor, NanoLetters, Article asap (2014)
E.J.H. Lee, X. Jiang, M. Houzet, R. Aguado, C.M. Lieber, S. De Franceschi, Spin-resolved Andreev levels and parity crossings in hybrid superconductor-semiconductor nanostructures, Nature Nanotechnology 9, 79 (2014)
N. Ares, V. N. Golovach, G. Katsaros, M. Stoffel, F. Fournel, L. I. Glazman, O. G. Schmidt, and S. De Franceschi, “On the nature of tunable hole g-factors in quantum dots”, Phys. Rev. Lett. 110, 046602 (2013)
Quantum spintronics aims at utilizing the quantum nature of individual spins to bring new functionalities into logic circuits, either to make classical information processing more efficient or to implement spin-based quantum algorithms. Two critical aspects for quantum spintronics are a long spin coherence time and a strong, tunable spin-orbit interaction for fast electrical manipulation of spins. Up to now, experiments have mainly focused on III-V semiconductor nanostructures, where hyperfine coupling with nuclear spins limits electron-spin coherence. Low nuclear spin materials, and in particular group-IV semiconductors, were found to be a natural alternative. However, in most of the currently studied group-IV based systems, spin-orbit coupling is very weak, preventing fast electrical manipulation of spins.
SiSPIN consortium proposes to investigate a new direction based on p-type SiGe nanostructures. This system has the unique combination of low hyperfine and strong spin-orbit couplings. Aside from developing demonstrator devices such as spin-filters or single spin qubits, the goal is to explore recently proposed schemes for long range spin-spin coupling, an essential requirement for scalable qubit circuits. To investigate hole-spin dynamics and achieve quantum spintronic functionalities, novel types of concepts will be experimentally investigated (spin-polarized helical states, spin-orbit mechanisms for spin-selective tunneling and long-range spin-spin coupling, etc.). Because of the higher complexity of hole-type systems, a dedicated theoretical framework will be developed in support to experiments. In addition to a bottom-up approach which has been successful in providing nanowire and quantum-dot heterostructures, SiGe quantum devices will be realized by means of state-of-the-art CMOS technology. This will allow to know how spin-based functionalities demonstrated in bottom-up nanostructures can be implemented into a truly scalable silicon platform.
In brief, the SiSPIN project is built upon very recent experimental, theoretical, and technological developments. It thus aims at exploring a radically new and promising approach to quantum spintronics whose novelty rests on an ensemble of the following original elements:
WP1-Synthesis of SiGe nanostructures and device fabrication:  Bottom-up growth of Ge/Si core/shell nanowires  Growth of SiGe self-assembled islands and hut wires  Implement hydrogen resist lithography with a p-type dopant  Top-down fabrication of quantum dots and wires based on state-of-the-art SGOI technology
WP2-DC transport properties and spin spectroscopy:  Determine structural parameters (size, quantum confinement, composition) of SiGe nanostructures for feedback to WP1  Measure fundamental properties of hole spins in SiGe nanostructures: g-factors, spin orbit coupling, helical states
WP3-Spin manipulation and spin-spin coupling:  Realize single SiGe spin qubits and measure the characteristic times for spin relaxation and dephasing  Couple two hole-spin qubits via a single high-Q superconducting resonator, and measure effective spin-spin coupling./p>
WP4-Modelling of hole-spin physics in low-dimensional systems:  Detailed theoretical understanding of hole-spin properties in Ge/Si quantum dots and nanowires  Prediction of lifetimes T1 (relaxation) and T2 (decoherence) for various experimental setups  Elaborate proposal for the implementation of long-range quantum gates for hole-spin qubits  Modelling of transport in Ge/Si wires via Luttinger liquid formalism with hole-hole interactionsp>
Knowledge lies at the heart of the European Union»s Lisbon Strategy to become the “most dynamic competitive knowledge-based economy in the world”. The «knowledge triangle» – research, education and innovation – is a core factor in European efforts to meet the ambitious Lisbon goals. Numerous programmes, initiatives and support measures are carried out at EU level in support of knowledge.
The Seventh Framework Programme (FP7) bundles all research-related EU initiatives together under a common roof playing a crucial role in reaching the goals of growth, competitiveness and employment; along with a new Competitiveness and Innovation Framework Programme (CIP), Education and Training programmes, and Structural and Cohesion Funds for regional convergence and competitiveness. It is also a key pillar for the European Research Area (ERA).
Future Emerging Technology (FET) - SiSPIN is a FET-Open project and thus part of a light, topic-agnostic and deadline free research funding scheme specifically designed to be open and continuously responsive to novel and fragile ideas that challenge current thinking, whenever they arise and wherever they come from.
FET-Open targets foundational breakthroughs that can open radically new directions for information and communication technologies in the future. It is one of the most selective calls of the FP7.
To find out more about the European 7the Framework Programme, please visit the European Commission website.
The CEA is the French Alternative Energies and Atomic Energy Commission (commissariat à l'énergie atomique et aux énergies alternatives). It is a public body established in October 1945 by General de Gaulle. A leader in research, development and innovation, the mission statement has two main objectives: to become the leading technological research organization in Europe and to ensure that the nuclear deterrent remains effective in the future.Visit the CEA website
The LaTEQS was established in 1996 as a part of the Institute for Nanosciences and Cryogeny (INAC), a joint research unit of the CEA with the University Joseph Fourier (Grenoble). The research activity embraces various aspects of mesoscopic quantum transport in nanostructures and low-dimensional systems: silicon nano-MOSFETs, self-assembled semiconductor nanostructures, carbon nanotubes, superconducting thin films, hybrid systems combining superconductors, normal conductors, and ferromagnets. In these systems we study the physics of individual confined electrons, as well as quantum phenomena resulting from strong electron-electron correlations (e.g. due to superconductivity, Coulomb interaction, Kondo effect, etc.). Our experimental tools range from low-noise electrical measurements, to current noise detection, specific-heat measurements, scanning-electron microscopy, time-resolved electrical measurements involving high-frequency signals, mostly at low temperature.Visit the CEA-INAC website
LETI, part of the CEA (French Atomic Energy Agency) is a research institute (on materials, processes and technologies) whose mission is to develop innovative solutions which lead to industrial transfers or start-up creation, and meanwhile to explore prospective fields in collaboration with academia. CEA-LETI has a strong experience in microelectronics, and especially in advanced CMOS technologies. Its activities cover the study of innovative substrates and devices for sub 22nm nodes. It has fabricated aggressive lengths MOS transistors on ultrathin SOI (Si thickness down to 2.5nm), strained-Silicon on Insulator (sSOI), SiGe-On-Insulator (SGOI) and GeOI substrates. CEA-LETI is focused on alternative solutions for CMOS down scaling (high-k dielectrics, metal gates, Raised Source/Drain, Metallic S/D…) and also on innovative CMOS integration schemes like nanowire transistors, multi-channel transistors and 3D integration of Ge on Si CMOS.Visit the CEA-LETI website
Delft University of Technology (TU Delft) was established in 1842. With over 14.000 students and a research staff of 2.100 it is the largest and most diverse engineering university in the Netherlands. Nanotechnology is one of the spearheads in its long-term strategic plans. Together with the two other Dutch Universities of Technology in Eindhoven and Twente, TU Delft has founded a national Institute of Science & Technology. In this partnership special funding from the Dutch government and from the separate institutions is directed towards selected topics, among which Nanoscience and Nanotechnology. Lastly, TU Delft participates in the National nanoscience program NanoNed, heading its ambitious technology program (NanoLab). As part of this program aimed at building up state-of-the-art nanotechnology labspace in the Netherlands, a major new nanofabrication cleanroom at TU Delft has been recently completed, co-funded by University funds.Visit the TU Delft website
The Quantum Transport group is part of The Kavli Institute of Nanoscience at TU Delft. The Institute comprises a senior research staff of over 30, an engineering support staff of 25, and 100 postdocs/PhD students. Among the other members of the prestigious league of Kavli Institutes are renowned universities such as Cornell, CalTech and Harvard (USA). Research at the Institute is internationally oriented, science-driven and often in collaboration with leading experts worldwide.Visit the Quantum Transport group website
IBM’s Zürich Research Laboratory (ZRL), with approximately 240 employees, 50 PhD and postdoctoral students, and 30 visiting scientists, is the European branch of the IBM Research Division with headquarters at the T.J. Watson Research Center in Yorktown Heights, NY, USA. Throughout the history of the Zürich Laboratory, scientists have made major contributions to the advancement of knowledge in solid-state physics, stimulated by problems relevant to technology. Most notably, the invention of scanning tunneling and atomic force microscopes and the discovery of high-temperature superconductivity were awarded Nobel prices. In spring 2011 IBM, in close partnership with ETH Zurich, opened the Binning and Rohrer Nanocenter, a state of the art 1000m2 clean-room including several labs offering an unprecedented noise-free environment.
The “Physics of Nanoscale Systems” group at IBM has strong expertise in the fields of growth/characterization of semiconductor and ferromagnetic materials, nanofabrication, scanning probe techniques, ultra-fast optical spectroscopy, and low-noise transport measurements.Visit the IBM Zurich website
The University of Copenhagen was founded in 1479, and currently has approximately 37,000 students and 7000 scientific, technical, and administrative staff. University of Copenhagen is the top ranked university in Denmark by the 2010 University Ranking by Academic Performance metric. The Niels Bohr Institute (NBI) unifies four institutes in the physical sciences, including Astronomy, Geophysics, Condensed Matter Physics at the Ørsted Laboratory, and the Niels Bohr Institute where theoretical high-energy physics, atomic and biophysics are located. The NBI comprises 10 research groups and 12 science centers, with approximately 700 students.Visit the University of Copenhagen website
Under sponsorship of the Danish National Research Foundation, the Center for Quantum Devices (QDev) was established 2012 in the Ørsted building. The focus of QDev is how to create, control, measure, and protect quantum coherence and entanglement in solid-state electronic.
QDev research facilities include seven cryogen-free Triton dilution refrigerators (Oxford Instruments) with 10T, 12T, 6-1-1T three-axis (x4), and 9-3 two-axis magnets configured for high-bandwidth measurements, as well as a cryogen-free 3He cryostat and low-temperature probe stations. Electron beam lithography facilities include Raith e-line 40kV and Elionix ELS-7000 100kV systems. Fabrication facilities include two AJA sputtering/electron beam evaporators, and conventional cleanroom tools, inspection scanning electron microscope and atomic force microscopy.Visit the Center for Quantum Devices website
The University of Basel, founded 1460, is the oldest University in Switzerland. The Department of Physics was the center of the activities of the Bernoullis, and Euler was educated there. In 2011, it was the highest ranked institute in Switzerland, and currently it is ranked among the top 25 worldwide, even among the top 5 regarding citations (see QS World University Rankings and ESI Web of Science). The focus of the Department is on Nanophysics and Astrophysics, and it conducts both experimental and theoretical research.Visit the University of Basel website
The research activities of the theory group include many aspects of the quantum theory of condensed matter, with a particular focus on spin-dependent and phase-coherent phenomena («mesoscopics») in molecular magnets and semiconducting nanostructures. A major portion of the group»s current research involves the theory of spin dynamics, nuclear spin effects, spin coherence, spintronics in two-dimensional electron gases, and spin-related phenomena in semiconducting quantum dots, artificial atoms and molecules, and in molecular magnets. Much of this work is related to quantum information processing (QIP) – quantum computing and quantum communication in solid-state and molecular systems with focus on spin qubits, where Loss and collaborators made seminal contributions. Their theoretical predictions and proposals have stimulated many further investigations, and in particular many experimental programs on spin qubits worldwide.Visit the Theory group website
The Johannes Kepler University of Linz is a public institution of higher education in Linz, the capital of Upper Austria. It offers bachelor»s, master»s, diploma and doctoral degrees in business, engineering, law, science, and the social sciences. Today, 19,300 students study at the park campus in the northeast of Linz, with 1 out of 9 students being from abroad. In 2012, the Times Higher Education ranked the JKU at #41 in its list of the top 100 universities under 50 years old.Visit the Johannes Kepler University of Linz website
The Institute of Semiconductor and Solid State Physics is focused on the fabrication and investigation of semiconductor hetero- and nanostructures and it is a major part of the center of “Nanoscience and Technology” of the Johannes Kepler University Linz. The research encompasses all aspects of semiconductor nanostructures, ranging from nanofabrication, fundamental investigations and modeling of physical properties up to the realization of novel nanostructure devices for spintronic and infrared optoelectronic applications. Nanostructures are fabricated using advanced lithography and processing techniques including electron beam lithography, holographic lithography, as well as self-assembled growth using molecular beam epitaxy. The objective of nanofabrication is to produce defect-free structures in the sub 50 nm range with good control of shapes and compositions, sharp heterointerfaces and excellent optical and electronic properties. A particular emphasis is on the development of site-control techniques for positioning of self-assembled nanostructures. From the materials side, a strong focus is on Si/SiGe based hetero- and nanostructures for which a molecular beam epitaxy system is operated in the clean room of the institute as well as another system devoted to in situ growth studies using scanning tunneling microscopy.Visit the Institute of Semiconductor and Solid State Physics website
Realization of quantum error correction in a semiconductor spin qubit system
Experimental investigation of spin qubits with all-electrical control in silicon-germanium based materials at the Center for Quantum Devices