The most sensitive and fastest graphene microwave bolometer

September 30, 2020

Bolometers are devices that measure the power of incident electromagnetic radiation thru the heating of materials, which exhibit a temperature-electric resistance dependence. These instruments are among the most sensitive detectors so far used for infrared radiation detection and are key tools for applications that range from advanced thermal imaging, night vision, infrared spectroscopy to observational astronomy, to name a few.

Even though they have proven to be excellent sensors for this specific range of radiation, the challenge lies in attaining high sensitivity, fast response time and strong light absorption, which not always are accomplished all together. Many studies have been conducted to obtain these higher-sensitivity bolometers by searching to reduce the size of the detector and thus increase the thermal response, and in doing so, they have found that graphene seems to be an excellent candidate for this.

If we focus on the infrared range, several experiments have demonstrated that if you take a sheet of graphene and place it in between two layers of superconducting material to create a Josephson junction, you can obtain a single photon detector device. At low temperatures, and in the absence of photons, a superconducting current flows through the device. When a single infrared photon passes through the detector, the heat it generates is enough to warm up the graphene, which alters the Josephson junction such that no superconducting current can flow. So you can actually detect the photons that are passing through the device by measuring the current. This can be done basically because graphene has an almost negligible electronic heat capacity. This means that, contrary to materials that retain heat like water, in the case of graphene a single low-energy photon can heat the detector enough to block the superconducting current, and then dissipate quickly, allowing the detector to rapidly reset, and thus achieving very fast time responses and high sensitivities.

Trying to take a step further and move to higher wavelengths, in a recent study published in Nature, a team of scientists which includes ICFO researcher Dmitri Efetov, together with colleagues from Harvard University, Raytheon BBN Technologies, MIT, and the National Institute for Material Sciences, has been able to develop a graphene-based bolometer that can detect microwave photons at extremely high sensitivities and with fast time responses.

Just like with the infrared range, the team took a sheet of graphene and placed it in between two layers of superconducting material to create a Josephson junction. This time, they went an entirely new route and attached a microwave resonator to generate the microwave photons and by passing these photons through the device, were able to reach an unprecedented detection levels. In particular, they were able to detect single photons with a much lower energy resolution, equivalent to that of a single 32 Ghz photon, and achieve detection readouts 100.000 times faster than the fastest nanowire bolometers constructed so far.

The results achieved in this study mean a major breakthrough in the field of bolometers. Not only has graphene proven to be an ideal material for infrared sensing and imaging, but it has also proven to span to higher wavelengths, reaching the microwave, where it has also shown to attain extremely high sensitivities and ultra-fast read out times.

As Prof. at ICFO Dmitri Efetov comments "such achievements were thought impossible with traditional materials, and graphene did the trick again. This open entirely new avenues for quantum sensors for quantum computation and quantum communication".
-end-
ABOUT ICFO

ICFO was founded by the Government of Catalonia and the Universitat Politècnica de Catalunya (UPC), both of which are members of its board of trustees along with the Cellex and Mir-Puig Foundations, philanthropic entities that have played a critical role in the advancement of the institute. Located in the Mediterranean Technology Park in the metropolitan area of Barcelona, the institute currently hosts 400 people, organized in 25 research groups in 60 state-of-the-art research laboratories. Research lines encompass diverse areas in which photonics plays a decisive role, with an emphasis on basic and applied themes relevant to medicine and biology, advanced imaging techniques, information technologies, a range of environmental sensors, tunable and ultra-fast lasers, quantum science, photovoltaics and the properties and applications of nano-materials such as graphene, among others. In addition to three state awarded Severo Ochoa accreditations of excellence, ICFOnians have secured 15 ICREA Professorships and 37 European Research Council grants. ICFO is proactive in fostering entrepreneurial activities, spin-off creation, and creating collaborations and links between industry and ICFO researchers. To date, ICFO has helped create 8 start-up companies.

ICFO-The Institute of Photonic Sciences

Related Graphene Articles from Brightsurf:

How to stack graphene up to four layers
IBS research team reports a novel method to grow multi-layered, single-crystalline graphene with a selected stacking order in a wafer scale.

Graphene-Adsorbate van der Waals bonding memory inspires 'smart' graphene sensors
Electric field modulation of the graphene-adsorbate interaction induces unique van der Waals (vdW) bonding which were previously assumed to be randomized by thermal energy after the electric field is turned off.

Graphene: It is all about the toppings
The way graphene interacts with other materials depends on how these materials are brought into contact with the graphene.

Discovery of graphene switch
Researchers at Japan Advanced Institute of Science and Technology (JAIST) successfully developed the special in-situ transmission electron microscope technique to measure the current-voltage curve of graphene nanoribbon (GNR) with observing the edge structure and found that the electrical conductance of narrow GNRs with a zigzag edge structure abruptly increased above the critical bias voltage, indicating that which they are expected to be applied to switching devices, which are the smallest in the world.

New 'brick' for nanotechnology: Graphene Nanomesh
Researchers at Japan advanced institute of science and technology (JAIST) successfully fabricated suspended graphene nanomesh (GNM) by using the focused helium ion beam technology.

Flatter graphene, faster electrons
Scientists from the Swiss Nanoscience Institute and the Department of Physics at the University of Basel developed a technique to flatten corrugations in graphene layers.

Graphene Flagship publishes handbook of graphene manufacturing
The EU-funded research project Graphene Flagship has published a comprehensive guide explaining how to produce and process graphene and related materials (GRMs).

How to induce magnetism in graphene
Graphene, a two-dimensional structure made of carbon, is a material with excellent mechani-cal, electronic and optical properties.

Graphene: The more you bend it, the softer it gets
New research by engineers at the University of Illinois combines atomic-scale experimentation with computer modeling to determine how much energy it takes to bend multilayer graphene -- a question that has eluded scientists since graphene was first isolated.

How do you know it's perfect graphene?
Scientists at the US Department of Energy's Ames Laboratory have discovered an indicator that reliably demonstrates a sample's high quality, and it was one that was hiding in plain sight for decades.

Read More: Graphene News and Graphene Current Events
Brightsurf.com is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to Amazon.com.