Contacts : Hakim Amara (hakim.amara @ onera.fr) et Lorenzo Sponza (lorenzo.sponza @ onera.fr)
Like many other technologies, new quantum devices rely heavily on materials whose structure and properties are not always under control. This is all the more true for low-dimensional materials with unique properties, which are at the heart of international research into the development of quantum technologies.
In this highly competitive environment, ONERA has real strengths, and is seeking to capitalize on its expertise in nanomaterials (nanotubes, 2D materials and their heterostructures) and in the reliability of devices in a radiative environment for second-generation quantum applications.
More specifically, the following research topics are developed by coupling experimental (synthesis/fabrication and characterization) and theoretical approaches at the atomic scale:
- Optimized 2D BN synthesis for optoelectronic devices
Hybridized boron nitride sp2 has established itself as an indispensable material in the family of 2D materials and their heterostructures, thanks to the nature of its lamellar structure and its wide electronic gap (> 6 eV). It has been demonstrated that atomically planar BN sheets used as carriers or encapsulating layers ideally preserve the properties of 2D materials for various optoelectronic devices. With this in mind, ONERA has for several years been developing a synthesis protocol for growing continuous monoriented BN layers on single-crystal Ni pseudosubstrates. The challenge now is to gain a detailed understanding of the growth mechanisms involved, in order to identify the parameters that enable deterministic control of layer synthesis. A particular effort will be made to correlate the qualification of the structural quality of the layers by electron microscopy techniques and optical spectroscopy techniques applicable right down to the devices.
- BN defect engineering for second-generation quantum engineering
2D materials are expected to be excellent candidates for second-generation quantum devices due to the high thermal and chemical stability of their defects, the ease of signal extraction, the high level of miniaturization that would enable and the high sensitivity to the near environment (proximity modulation and sensors). Among defects, our research efforts are focused on BN and more specifically on (i) the stacking of two twisted layers giving rise to a robust two-level state or (ii) the engineering of point defects as a source of single photons.
- Carbon nanotubes: an ideal candidate for QUBITS
Quantum computing is a fast-developing technology which seeks to exploit the principle of superposition derived from quantum mechanics to solve problems that have hitherto been too complex for today's computers. The main advantage of carbon nanotubes is their ability to confine a charge in a solid environment, thus improving the protection of trapped electrons and the coherence time of qubits. Among the challenges that ONERA is seeking to overcome in the development of carbon nanotube-based quantum computing, the main one lies in the use of tubes whose structure (diameter, helicity) is perfectly controlled to obtain nano-objects with defined electronic properties.
- The reliability of QUBITS in a natural radiative environment
Unlike a classical calculator, based on transistors working on binary data (coded on bits, worth 0 or 1), the quantum calculator works on QUBITS whose quantum state can have several values, or more precisely a quantum value with several simultaneous possibilities. Currently, the critical parameter for the reliability of these devices is the retention time of the processed information. This time can be strongly affected by the computer's immediate environment, such as temperature and radiation. In this context, ONERA is seeking to determine the contribution of cosmic radiation to the reliability of QUBITS by identifying the physical mechanisms disrupting the nominal behavior of Cooper pairs in superconducting materials such as aluminum and carbon nanotubes.