Project description
An unprecedented experimental platform could spur progress in quantum computing
Quantum bits, or qubits, can store and process so much more information that a conventional bit because they can be in two states at the same time. Unfortunately, these quantum effects are very fragile, and any external influences can cause the qubit to 'collapse'. Scientists are now talking about topological quantum computers that will encode their qubits in a type of quasiparticle we are not even sure exists. The so-called topological properties of these quasiparticles make them particularly robust to outside interference. The EU-funded TOCINA project is developing a novel experimental platform that will enable scientists to explore these foundations in ways not previously possible.
Objective
The key challenge in quantum computation is decoherence - the collapse of a quantum state due to local perturbations. In this proposal we address this challenge by developing a new nanomaterials system, which forms the core of a future topological quantum computer. In a topological quantum bit, information is encoded in Majorana modes, which are topologically protected by a local symmetry and therefore have long coherence times.
In this project we develop a new state of matter -topological crystalline insulator nanowires- in which the topology is defined by the band inversion and the crystal symmetry of the material. Therefore, these topological states should be exceptionally robust. Further, we integrate strong superconductors on these nanowires. These two features together should increase the energy scales of the system compared to current state-of-the-art devices, and therefore lead to stable and electrically-isolated Majorana states.
In this project we develop new crystal growth strategies, which enable to grow out-of-thermodynamic equilibrium structures. We will be the first to employ Molecular Beam Epitaxy (MBE) to precisely tune the SnTe nanowire growth conditions. We use the directionality offered by MBE to shadow-grow superconductors on one nanowire facet. The in-situ ultra-high-vacuum growth of hybrid semiconductor/superconductor devices will result in unprecedented device quality.
Due to the increased energy scales, experiments, which have been unattainable so far, come within reach. We use this new materials platform to demonstrate entanglement of two Majorana modes at the ends of a nanowire. This quantum teleportation is a groundbreaking experiment and is the key of a topological quantum computer.
Fields of science
- engineering and technologymaterials engineeringcrystals
- natural sciencesmathematicspure mathematicstopology
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcomputer hardwarequantum computers
- natural sciencesphysical scienceselectromagnetism and electronicssemiconductivity
- natural sciencesphysical scienceselectromagnetism and electronicssuperconductivity
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Funding Scheme
ERC-ADG - Advanced GrantHost institution
5612 AE Eindhoven
Netherlands