Diamond with Sp2-Sp3 composite phase for thermometry at Millikelvin temperatures

• Published in: Nature communications 2024-05, Vol.15 (1), p.3871-3871, Article 3871
• Main Authors: Yin, Jianan, Yan, Yang, Miao, Mulin, Tang, Jiayin, Jiang, Jiali, Liu, Hui, Chen, Yuhan, Chen, Yinxian, Lyu, Fucong, Mao, Zhengyi, He, Yunhu, Wan, Lei, Zhou, Binbin, Lu, Jian
• Format: Article
• Language: English
• Subjects: 140/133; 140/146; 147/135; 147/143; 639/301/1005/1007; 639/301/1005/1009; Absolute zero; Cryogenic temperature; Humanities and Social Sciences; Low temperature; Magnetic fields; multidisciplinary; Physics; Quantum computing; Quantum theory; Science; Science (multidisciplinary); Sensors; Temperature; Temperature measurement; Temperature sensors; Thermal stability; Thermometry
• ISSN: 2041-1723; 2041-1723
• DOI: 10.1038/s41467-024-48137-z

Temperature is one of the seven fundamental physical quantities. The ability to measure temperatures approaching absolute zero has driven numerous advances in low-temperature physics and quantum physics. Currently, millikelvin temperatures and below are measured through the characterization of a certain thermal state of the system as there is no traditional thermometer capable of measuring temperatures at such low levels. In this study, we develop a kind of diamond with sp 2 - sp 3 composite phase to tackle this problem. The synthesized composite phase diamond (CPD) exhibits a negative temperature coefficient, providing an excellent fit across a broad temperature range, and reaching a temperature measurement limit of 1 mK. Additionally, the CPD demonstrates low magnetic field sensitivity and excellent thermal stability, and can be fabricated into probes down to 1 micron in diameter, making it a promising candidate for the manufacture of next-generation cryogenic temperature sensors. This development is significant for the low-temperature physics researches, and can help facilitate the transition of quantum computing, quantum simulation, and other related technologies from research to practical applications. To measure temperatures close to absolute zero, authors developed a kind of composite phase diamond (CPD) that can measure temperature at the millikelvin level, making it a promising candidate for next–generation cryogenic temperature sensors.