IBM Engineers Develop Nanoscopic Thermometer, Enabling Precise Temperature Mapping of Quantum Devices

The IBM laboratory that pioneered the scanning tunneling microscope (STM) and atomic force microscope (AFM) has introduced a new, indispensable tool for nanoscale research: a scanning probe thermometer capable of measuring temperatures with millikelvin precision.

Accurately gauging the temperature of objects at the nanometer scale has long posed a challenge. Existing methods are either inaccurate or introduce measurement artifacts that compromise reliability.

Motivated by the need to characterize next‑generation transistor designs for cognitive computing, IBM scientists in Switzerland, in collaboration with ETH Zurich, unveiled a breakthrough technique. The patent‑pending invention is described in the peer‑review journal Nature Communications under the title “Temperature mapping of operating nanoscale devices by scanning probe thermometry.”

History of Innovation

In the 1980s, IBM researchers Gerd Binnig and the late Heinrich Rohrer recognized that existing instruments could not directly probe a surface’s electronic structure. They invented the STM, a decision that earned them the 1986 Nobel Prize in Physics and opened the field of nanotechnology.

Now, more than three decades later, IBM scientists are following that pioneering spirit with a thermometer designed for the nanoscale.

Dr. Fabian Menges, an IBM post‑doc and co‑inventor, notes, “We began in 2010 and remained relentless. Earlier work focused on a nanoscale thermometer, but we re‑envisioned it as a thermometer for the nanoscale—an essential distinction that led to our scanning probe thermometry approach.”

How Scanning Probe Thermometry Works

Traditional temperature measurements involve bringing a thermometer into thermal contact with a sample, allowing it to equilibrate. While this works on the macroscale, it fails at the nanoscale where the probe cannot equilibrate without perturbing the sample—think of trying to measure a virus’s temperature with a conventional thermometer.

IBM’s solution is a non‑equilibrium, single‑scan technique that captures two simultaneous signals: the heat flux into the probe and the resistance to heat flow. By combining these measurements, the method accurately quantifies the temperature of nanoscopic objects.

Dr. Bernd Gotsmann explains, “It’s like touching a hot plate and inferring its temperature from the heat flux between your hand and the plate. The probe’s tip acts as the hand; knowing the heat resistance is essential for an accurate estimate.”

The team validated the technique on an indium arsenide (InAs) nanowire and a self‑heated gold interconnect, achieving spatial resolution of a few nanometers and temperature resolution of a few millikelvin.

Applications and Impact

Menges highlights that the scanner is not only accurate but also user‑friendly, simple to build, and versatile. It can measure temperature hotspots in nano‑ and micro‑devices, influencing material properties and guiding reactions in transistors, memory cells, thermoelectric converters, and plasmonic structures.

Noise‑Free Labs

Development of the thermometer accelerated after the team relocated to the Noise Free Labs—six meters underground at the Binnig and Rohrer Nanotechnology Center. This environment eliminates vibration, acoustic noise, electromagnetic interference, and temperature fluctuations, enabling sub‑millikelvin precision.

“Even outside this controlled setting, the technique delivers reliable results,” says Menges.

Future Outlook

Gotsmann expresses optimism: “We anticipate that this work will spark excitement and relief among researchers seeking such a tool. Like the STM, we hope to license the technology to manufacturers, integrating it into next‑generation microscopy suites.”

The scientists acknowledge support from the 7th Program Framework under the NANOHEAT project and the Swiss National Science Foundation.