Graphene based nanosensors

Exploiting coupling between single emitters and graphene

Artistic picture of our test sample, where a DBT:anthracene crystal is interfaced with a graphene monolayer sheet.
Artistic picture of our test sample, where a DBT:anthracene crystal is interfaced with a graphene monolayer sheet.

Among many different materials, graphene — a one-atom-thick layer of carbon atoms — though available in high-quality samples for less than a decade, has already made an impressive debut in nanophotonics, due to its unique electronic, mechanical and optical properties. From a fundamental point of view, the proximity of a quantum emitter to this purely two-dimensional material is still unexplored, although it potentially allows to explore new limits of light-matter interaction [1].

Given the relatively low costs and ease of fabrication of both systems, the hybrid system made of DBT:Anth crystals coupled to graphene would be an original and promising test bed for the study of strong light-matter interaction. Moreover the enhancement and tunability of light-matter interaction achievable in these hybrid nanostructures promise new fundamental insight as well as potential applications, ranging from sensing to quantum computing.

A proof of principle for a graphene based nanoruler

We investigated the coupling of single molecules to a mono-atomic graphene layer in a specific distance and energy range in which the main mechanism of energy relaxation is the non-radiative energy transfer to graphene. This process was thoroughly characterized by measuring the molecule excited state lifetime and the agreement between the experimental results and a very simple theoretical model enabled the claim for a proof of principle of a graphene-based nanoruler [2-3].

Exploiting Casimir forces

We are currently working on the development of a device for quantum position sensing made of a suspended graphene sheet suspended on top of a test chips with multiple arrays of holes filled with DBT:Anth crystals. At low temperature, this configuration would allow to study and accurately measure the Casimir forces between individual molecules and the graphene membrane [4]. Their interaction is indeed predicted to yield a transition frequency shift of the single emitter which can be read out detecting the field scattered by individual molecule. As the frequency shift strongly depends on the separation distance between single emitters and the graphene layer, this system would represent the first practical scheme for quantum sensing.

References

  • [1] F. J. Garcia de Abajo. Graphene nanophotonics, Science, vol. 339, no. 6122, pp. 917–918, 2013.
  • [2] C. A. Muschik, S. Moulieras, M. Lewenstein, F. Koppens, and D. Chang. Universal distance-scaling of nonradiative energy transfer to graphene, Nano Letters, vol. 13, no. 5, pp. 2030–2035..
  • [3] G. Mazzamuto, A. Tabani, S. Pazzagli, S. Rizvi, A. Reserbat-Plantey, K. Schädler, G. Navickaite, L. Gaudreau, F. S. Cataliotti, F. Koppens and C. Toninelli. Single-molecule study for a graphene-based nano-position sensor, New Journal of Physics, 16 113007, 4 Nov 2014.
  • [4] L. Gaudreau, K. Tielrooij, G. Prawiroatmodjo, J. Osmond, F. G. de Abajo, and F. Koppens. Harnessing vacuum forces for quantum sensing of graphene motion, Phys. Rev. Lett. 112, 223601 (2014).

Publications

Other research topics

Single photon sources

Single photon sources

Dibenzoterrylene (DBT) molecules hosted in thin anthracene crystals are a versatile single photon source system. We study their coupling with external nanostructures.

Antennas: Light-shaping and Plasmonics

Antennas: Light-shaping and Plasmonics

Plasmonic structures prove as test beds for studying light-matter interaction at the fundamental level, while versatile hybrid antennas provide excellent means to modulate emission patterns for various applications.

Random photonic structures

Random photonic structures

We exploit the interplay between order and disorder to control the onset of Anderson localized quasimodes in photonic slabs.

Transport in turbid media

Transport in turbid media

Monte Carlo simulations provide an exact solution for the Radiative Transfer Equation in turbid media, overcoming the limits of the diffusive approximation.