Microwave quantum sensing with diamond color centers – MICROSENS

We are building two different prototypes of microwave sensors based on the NV spin properties: a single microwave photon detector and a wideband quantum spectrum analyser. Theoretical aspects are also jointly addressed by the MICROSENS proposal since understanding the ultimate limits of noise for high-frequency spin sensing is one of the main objectives of the MICROSENS proposal.

To achieve those goals, a room-temperature cavity-QED setup has been constructed involving a microwave cavity and a diamond densely doped with NV centers. Pulsed quantum control has been implemented in this setup. This is an important milestone on the way to achieve microwave photon detection with such a set-up.
The spectral range of the spectrum analyser has been extended to cover a large part of the radar frequency range. The sensitivity has been improved at low frequency range. Achieving high sensitivity at higher frequency would require optimization of the antenna. The spectral resolution has been improved supressing the natural hyperfine structure of NV centre resonances by optical pumping.
The sensitivity of the measurements has been improved using dynamical decoupling and double resonance techniques. These techniques are compatible with high density of NV’s and allow reaching unprecedented sensitivity for ensemble magnetometry.
Diamond crystals have been grown along the 113 or 111 direction to favour one the four possible NV directions and thus enhance the coupling with the microwave field. Almost perfect orientation has been observed with diamond crystals grown along 111. Using a 12C isotope enriched diamond, an increase of the coherence time of the NV centers has been observed. Therefore the hyperfine structure is clearly visible. To increase the strength of the coupling, diamond crystals with very high density of NV centers (red diamond) have been produced and will further be evaluated in the consortium. Creation of conducting wires in the diamond is under development.

During the first part of the projects we have developed the first elements of the microwave single photon detector and microwave spectrum analyser. In the following part we will further improve the performances of those devices in order to achieve a significant impact in all fields of quantum technology.

Peer reviewed papers

1. Optimizing synthetic diamond samples for quantum sensing technologies by tuning the growth temperature; S. Chouaieb, L.J. Martínez, W. Akhtar, I. Robert-Philip, A. Dréau, O. Brinza, J. Achard, A. Tallaire, V. Jacques, Diam. Relat. Mat., 96, pp 85-89 (2019), www.sciencedirect.com/science/article/pii/S0925963519301700

2. Osterkamp et.al., Engineering preferentially-aligned nitrogen-vacancy centre ensembles in CVD grown diamond. Scientific Reports 2019, 9, 5786.

3. Zhou et.al., Quantum Metrology with Strongly Interacting Spin Systems. arXiv e-prints 2019, arXiv:1907.10066

4. A. Tallaire, O. Brinza, M. De Feudis, A. Ferrier, N. Touati, L. Binet, L. Nicolas, T. Delord, G. Hétet, T. Herzig, S. Pezzagna, P. Goldner, J. Achard, Synthesis of Loose Nanodiamonds Containing Nitrogen-Vacancy Centers for Magnetic and Thermal

Selected conferences (french partners)

1. J. Achard et al, Engineering doped single crystal diamond films for electronic and quantum applications; Fall Meeting MRS 2018, Boston, USA, 26 - 30 November 2018 (Invited)

2. J. Achard et al, Towards optimized (113) doped diamond films with NV colour centres for quantum sensing, ICDCM 2019, Seville, Spain, 8-12 September 2019

3. J. Achard et al, Engineering Doped Single Crystal Diamond Films For Quantum Applications, Quantum 2019, Torini, Italy, 26 May-1 June 2019 (Invited)

4. M. De Feudis et al, NV, SiV and GeV centers incorporated into CVD nanodiamonds : study of the growth process and the optical properties, Quantum 2019, Torino 26 May-1 June (2019)

5. L. Mayer et al., European Material Research Society Fall Meeting, Varsovie septembre 2018

6. T. Debuisschert et al., Heraeus Seminar, Bad Honnef, 25-27 mars 2019

Detection and spectroscopy of weak microwave (>GHz) signals is of pivotal importance for key areas of modern technology, including wireless communication, radar, navigation and medical imaging. Solid state spins could be attractive sensors for both tasks since they have transition frequencies that can be tuned across the 1-100 GHz range. However high-frequency sensing by solid state spins has remained underexplored so far, and most demonstrations of spin sensing have focused on low-frequency (<10MHz) signals. The main reason is that well-established quantum sensing protocols suffer from a low efficiency in the high frequency domain. Furthermore, implementation of spin quantum sensors is not as mature compared to highly developed integrated microwave electronics.
The purpose of the MICROSENS proposal is to use the well-known Nitrogen-Vacancy (NV) diamond color center as a tool to address these issues. We will build two different prototypes of microwave sensors based on the NV spin properties. The first one will be a single microwave photon detector and the second will be a wideband quantum spectrum analyser. Theoretical aspects will also be jointly addressed by the MICROSENS proposal since understanding the ultimate limits of noise for high-frequency spin sensing will be one of the main objectives of the MICROSENS proposal.
Led by an industrial partner, MICROSENS federates leading European groups of experimental materials science, solid-state spin sensing and cavity QED. MICROSENS thereby brings together all the necessary blocks to achieve the ambitious target of produce MW detectors with outstanding performances occurring from the quantum properties of the probe.

Research Targeted in the Call:
MICROSENS will invent spin quantum sensors for detection and spectroscopy of weak microwave signals, bridging the research fields of spin sensors and microwave cavity-QED.
Compared to conventional electronics, the resulting devices could be disruptive both in terms of sensitivity (down to single microwave photons) and simplicity (integration into IC-scale devices has been pioneered by the coordinator). We expect them to generate significant impact in several areas:
Quantum-communication: where efficient detectors could pave the way to cryptography using microwave photons, potentially reaching across longer scales than conventional optics.
Quantum computing: by studying transfer of short-lived fast processing qubits (microwave photons) to a long-lived memory (single spin).
Quantum information sciences: by studying and applying a problem of nonequilibrium quantum thermodynamics, the interaction of an ultracold (mK) spin with a cold (K) photonic bath, mediated by a high-temperature (100K) cavity.
Quantum metrology and sensing: by investigating protocols to suppress decoherence and sensitize spin sensors to microwave signals; by assessing their performance in real-world devices and their potential impact in radar, communication, navigation and medical imaging.