Quantum memories with 125Te+ donors implanted in silicon

Lead Research Organisation: University College London
Department Name: London Centre for Nanotechnology


Superconducting qubits, which are essentially collective excitations in superconductive circuits, are one of the leading platforms for the realisation of quantum computing, which would bring revolutionary changes to multiple fields such as chemistry, materials science and security. Currently, it is estimated that a million superconducting qubits will be needed for performing sufficiently error-corrected operations, but the implementation of a quantum memory in the circuit would reduce that number to the order of tens of thousands of qubits, which is much more technically feasible. Existing quantum memories either do not operate in the frequency range of superconducting qubits or their ability to store information is too short-lived and prone to error. By implanting ions of tellurium in a silicon substrate, an electron spin ensemble is created which collectively stores quantum states with long coherence times. Tellurium ions in particular are expected to allow transfer of information with sufficient fidelity via a superconducting resonator fabricated on the silicon sample, which drives a microwave magnetic field. Optimising the way the resonator communicates with the spin ensemble will be key to developing a quantum memory. Quantum memories with 125Te+ donors implanted in silicon also have the advantage of potentially operating at zero magnetic field, which will be crucial for future implementations of quantum memories next to superconducting qubits.

Planned Impact

The first and most important impact of our Centre will be through the cross-disciplinary technical training it provides for its students. Through this training, they will have not only skills to control and exploit quantum physics in new ways, but also the background in device engineering and information science to bring these ideas to implementation and to seek out new applications. Our commercial and governmental partners tell us how important these skills are in the growing number of people they are hiring in the field of quantum technologies. In the longer term we expect our graduates to be prominent in the development of new technologies and their application to communication, information processing, and measurement science in leading university and government laboratories as well as in commercial research and development. In the shorter term we expect them to be carrying out doctoral research of the highest international quality.

Second, impact will also flow from the students' approach to enterprise and technology transfer. From the outset they will be encouraged to think about the value of intellectual property, the opportunity it provides, and the fundraising needed to support research and development. As students with this mindset come to play a prominent part in university and commercial laboratories, their common background will help to break down the traditional barriers between these sectors and deliver the promise of quantum technologies for the benefit of the UK and world economies. Concrete actions to accelerate this impact will include entrepreneurship training and an annual CDT industry day.

Third, through the participation it nucleates in the training programme and in students' research, the Centre will bring together a community of partners from industry and government laboratories. In the short term this will facilitate new collaborations and networks involving the partners and the students; in the long term it will help to ensure that the supply of highly skilled people from the CDT reaches the parts of industry that need them most.

Finally, the CDT will have a strong impact on the quantum technologies training landscape in the UK. The Centre will organise training events and workshops open to all doctoral researchers to attend. We will also collaborate with CDTs in the quantum technologies and related research areas to coordinate our efforts and maximise our joint impact. Working in consort, these CDTs will form a vibrant national training network benefitting the entire UK doctoral research community.


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Studentship Projects

Project Reference Relationship Related To Start End Student Name
EP/S021582/1 01/10/2019 31/03/2028
2407166 Studentship EP/S021582/1 01/10/2020 30/09/2024 Ana Villanueva Ruiz De Temino