Graphene Helps Catch Light Quanta

September 11, 2017

Top view of the PC structure overlaid with the mode profile. Credit: ICFO*.

Considerable interest in new single-photon detector technologies has been scaling in this past decade. Nowadays, quantum optics and quantum information applications are, among others, one of the main precursors for the accelerated development of single-photon detectors. Capable of sensing an increase in temperature of an individual absorbed photon, they can be used to help us study and understand, for example, galaxy formation through the cosmic infrared background, observe entanglement of superconducting qubits or improve quantum key distribution methods for ultra-secure communications.

Current detectors are efficient at detecting incoming photons that have relatively high energies, but their sensitivity drastically decreases for low frequency, low energy photons. In recent years, graphene has shown to be an exceptionally efficient photo-detector for a wide range of the electromagnetic spectrum, enabling new types of applications for this field. Thus, in a recent paper published in the journal Physical Review Applied, and highlighted in APS Physics, ICFO researcher and group leader Prof. Dmitri Efetov, in collaboration with researchers from Harvard University [Prof. Philip Kim], MIT, Raytheon BBN Technologies and Pohang University of Science and Technology, have proposed the use of graphene-based Josephson junctions (GJJs) to detect single photons in a wide electromagnetic spectrum, ranging from the visible down to the low end of radio frequencies, in the gigahertz range...

Continue reading "Graphene single photon detectors' on, September 6, 2017

*Also read the research article: Evan D. Walsh, Dmitri K. Efetov, Gil-Ho Lee, Mikkel Heuck, Jesse Crossno, Thomas A. Ohki, Philip Kim, Dirk Englund, and Kin Chung Fong, "Graphene-Based Josephson-Junction Single-Photon Detector," Phys. Rev. Applied 8 (24 Aug 2017) DOI: