Zeptojoule Microwave Calorimetry with Nanosecond Recovery in Graphene

Year: 2026

Type: preprint

Abstract: Graphene calorimeters are predicted to combine extreme energy sensitivity with rapid thermal recovery, yet experiments remain far from ideal estimates. Here, we directly calibrate a graphene Josephson-junction microwave calorimeter using nanosecond pulses and independently determine the thermal parameters of the same operating device. At 110 mK, calibrated pulse measurements yield a characteristic switching-energy scale of 18.1 meV (2.90 zJ), while time-resolved two-pulse thermometry gives an intrinsic relaxation time of 19.5 ns. Pulse-width-dependent calorimetry and bolometric thermometry show that the electronic heat capacity is 12.4 times and the electron-phonon coupling is approximately 50 times larger than ideal estimates. A thermal model using these measured parameters predicts 21.2 meV, quantitatively reproducing the observed switching response. These results identify the microscopic origin of the sensitivity gap in graphene calorimeters and establish a self-consistent calibration framework for ultrafast nanoscale thermal detectors.

Source: arXiv (Cornell University)

DOI: 10.48550/arxiv.2610.33414

Authors: Lee, Seunghan, Jung, Woochan, Kim, Jayeon, Park, Dongsung T., Jang, Seong, Jeon, Seongeun, Watanabe, Kenji, Taniguchi, Takashi, Park, Jong-Chul, Kim, Philip, Fong, Kin Chung, Lee, Gil-Ho

Institutions: Pohang University of Science and Technology, Northeastern University, National Institute for Materials Science, Research Center for Materials Nanoarchitectonics, Chungnam National University, Harvard University

Language: English

Topic: Superconducting and THz Device Technology

Subfield: Electrical and Electronic Engineering

Field: Engineering

Domain: Physical Sciences

Open Access status: green

Funders: Asian Office of Aerospace Research and Development, Ministry of Education, Culture, Sports, Science and Technology, Pohang University of Science and Technology, Korea Basic Science Institute, National Research Foundation of Korea, Agency for Defense Development, Iran Telecommunication Research Center, Ministry of Science and ICT, South Korea, Samsung Science and Technology Foundation, Japan Society for the Promotion of Science, Defense Acquisition Program Administration, Institute for Information and Communications Technology Promotion

OpenAlex ID: W7223929524