Project description
Hybrid qubits to overcome key hurdles to realising a universal quantum computer
The essence of a universal quantum computer is that it combines the full power of a classical computer with that of a quantum computer, enabling simulation of physics and all operations of a classical computer. The spins of electrons embedded in a quantum dot or topological particles in semiconductors offer hope for building a universal quantum logic gate that supports all possible operations at the quantum mechanical level. However, both present challenges. The EU-funded QUIST project aims to unite both methods to overcome hurdles to building a large-scale quantum computer. The ultimate aim is to build a powerful platform where complex systems can be created, simulated, and computed to advance general understanding of physics.
Objective
The promise of universal quantum computation stems from the remarkable behaviour of quantum states and the challenge is to gain control over their fragile nature. In topological quantum computation, information can be encoded nonlocally on Majorana states to provide inherent protection against noise, but operation is restricted to the trivial Clifford group. Spins in quantum dots do provide universal logic, but interactions are short-ranged. I propose to study the question whether these platforms can be united to overcome their limitations as a path toward large-scale quantum computation.
The grand goal of this project is, therefore, to coherently transfer quantum information between spin and topological qubits. Our quantum material of choice is germanium, which can exhibit strong spin-orbit coupling, can provide long quantum coherence for single spins, and can make ohmic contacts to superconductors for hybrid superconductor-semiconductor systems. We will use two-dimensional germanium hetero structures and fabricate superconducting quantum dot devices. Qubits defined on the spin states of single holes will be electrically driven using the spin-orbit interaction and coupled through the exchange interaction. On linear chains of quantum dots we will pursue topological superconductivity, which we will consequently integrate in the spin qubit platform. We will then study their interaction to demonstrate controllable transfer of quantum information between hole spin and Majorana states.
This research is presently at a fundamental stage and is thereby bound to produce exciting results where new physics may arise. The choice of the materials platform and its compatibility with semiconductor manufacturing promises for a successful adoption as building block for future quantum technology. Our long-term dream is to create a powerful platform where complex and emerging systems can be created, simulated, and computed to advance our general understanding of physics.
Fields of science
- engineering and technologyelectrical engineering, electronic engineering, information engineeringelectronic engineeringcomputer hardwarequantum computers
- natural sciencesphysical scienceselectromagnetism and electronicssemiconductivity
- natural scienceschemical sciencesinorganic chemistrymetalloids
- natural sciencesphysical scienceselectromagnetism and electronicssuperconductivity
Programme(s)
Topic(s)
Funding Scheme
ERC-STG - Starting GrantHost institution
2628 CN Delft
Netherlands