SMERC · Strong Microwave Erbium Coupling
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2019-01-01 → 2020-12-31
- EU contribution
- €185,076
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
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Results in brief
Strong Microwave Erbium Coupling
Context Building quantum machines that process information more efficiently than their classical counterpart is an active field of research worldwide. One of the architectures that is pursued is that of a quantum network, consisting of quantum nodes connected by coherent links. Each quantum node includes a small number (approximately 5 to 10) of very coherent qubits, possibly serving as quantum memory. Coherent interfacing between the nodes is done by exchanging photons, in the form of visible light or microwave signals. Such a quantum network would enable distributed quantum computing and long-distance quantum key distribution through quantum repeaters. For quantum networks, crystals doped with erbium are one of the most appealing systems because of Erbium unique properties. Erbium is a member of the rare-earth elements, which can be found at the bottom of the periodic table. In particular, erbium can absorb and emit light at “telecom” wavelength, which is ideal for sending optical data through optical fibres. Indeed, this key property of erbium made the Internet possible through the use of erbium-doped lasers and amplifiers. Additionally, erbium ions have large magnetic moments. This is common property amongst many rare-earths; Neodymium magnets are used in many industrial applications. Erbium, however, has one of the largest magnetic moments of all the rare-earth elements. Because of this property erbium ions can couple strongly to both surrounding nuclei (providing a quantum register or “bus”) and also to microwave photons in a superconducting circuit. In this way, erbium could be used as a microwave-to-optical converter thanks to its telecom-wavelength optical transition. Project objectives In that context, project SMERC has been able to provide answers to the following questions : 1) Does the quantum “coherence” of the Erbium ion’s magnetic electron-spin transition persist for a long time? 2) Can erbium ions be strongly coupled to microwave photons in a superconducting resonator? The answers to these questions represent important milestones towards the realization of erbium-based quantum networks.
Data: CORDIS, © European Union
Project objective
Electronic and nuclear spins in solids have remarkable coherence properties which makes them ideal qubit candidates for future quantum computers. However, microwave detection and coupling of individual spins remains an outstanding challenge, and this is the main obstacle to their use for quantum computing. The rare earth element erbium (Er) is a very promising candidate for single-spin detection due to its exceedingly large electronic ground-state moment (J=15/2). Furthermore, Er has recently demonstrated 1.3 second hyperfine spin coherence (https://arxiv.org/abs/1611.0431), thus joining a very short list of solid state defects with coherence times of over a second. The Strong Microwave Erbium Coupling (SMERC) proposal aims to use superconducting circuits consisting of resonators and Josephson qubits to detect and couple individual Er spins in crystalline matrices.The superconducting circuits will be designed so as to enhance their magnetic coupling to the individual Er spins. In particular, nanoscale constrictions will be used to concentrate the microwave magnetic field at the Er ion location. This will result in Er-microwave photon coupling constants sufficient to detect a single Er spin within less than a millisecond integration time with microwave signals.
Original text from CORDIS.
Participants
- COMMISSARIAT A L ENERGIE ATOMIQUE ET AUX ENERGIES ALTERNATIVES · ParisCoordinatorFrance
Links
Data: CORDIS, © European Union