Physical phenomenon
Pomeranchuk cooling (named after Isaak Pomeranchuk ) is the phenomenon in which liquid helium-3 will cool if it is compressed isentropically when it is below 0.3 K. This occurs because helium-3 has the unusual property that its solid state can have a higher entropy than its liquid state. The effect was first observed by Yuri Anufriev in 1965.[ 1] cryogenic cooler .[ 2]
In 2021 an analog effect has been observed on twisted bilayer graphene [ 3] [ 4] [ 5] TMDs [ 6]
References
^ Lee, David M. (1 July 1997). "The extraordinary phases of liquid ${}^{3}$He" . Reviews of Modern Physics . 69 (3): 645– 666. doi :10.1103/RevModPhys.69.645 ^ Weisstein, Eric. "Pomeranchuk Cooling" . Eric Weisstein's World of Science . ^ "Electrons in twisted graphene 'freeze' when heated" . Physics World . 2021-04-21. Retrieved 2021-11-21 .^ Rozen, Asaf; Park, Jeong Min; Zondiner, Uri; Cao, Yuan; Rodan-Legrain, Daniel; Taniguchi, Takashi; Watanabe, Kenji; Oreg, Yuval; Stern, Ady; Berg, Erez; Jarillo-Herrero, Pablo (April 2021). "Entropic evidence for a Pomeranchuk effect in magic-angle graphene" . Nature . 592 (7853): 214– 219. arXiv :2009.01836 doi :10.1038/s41586-021-03319-3 . ISSN 1476-4687 . PMID 33828314 . S2CID 221516628 . ^ Ablikim, M.; Achasov, M. N.; Adlarson, P.; Ahmed, S.; Albrecht, M.; Aliberti, R.; Amoroso, A.; An, Q.; Lavania, Anita; Bai, X. H.; Bai, Y. (November 2021). "Oscillating features in the electromagnetic structure of the neutron" . Nature Physics . 17 (11): 1200– 1204. arXiv :2103.12486 doi :10.1038/s41567-021-01345-6 . ISSN 1745-2481 . S2CID 243888280 . ^ Li, Tingxin; Jiang, Shengwei; Li, Lizhong; Zhang, Yang; Kang, Kaifei; Zhu, Jiacheng; Watanabe, Kenji; Taniguchi, Takashi; Chowdhury, Debanjan; Fu, Liang; Shan, Jie; Mak, Kin Fai (September 2021). "Continuous Mott transition in semiconductor moiré superlattices" . Nature . 597 (7876): 350– 354. arXiv :2103.09779 doi :10.1038/s41586-021-03853-0 . ISSN 1476-4687 . PMID 34526709 . S2CID 232257656 .
