# Allan H. MacDonald

Allan H. MacDonald (born December 1, 1951) is a theoretical condensed matter physicist and the Sid W. Richardson Foundation Regents Chair Professor of Physics at The University of Texas at Austin. His research interests are centered on the electronic properties of electrons in metals and semiconductors. He is well known for his work on correlated many-electron states in low-dimensional systems. In 2020, he became one of the laureates of the Wolf Prize in Physics, for predicting the magic angle that turns twisted bilayer graphene into a superconductor.

## Education and early life

He was born in Antigonish, Nova Scotia, Canada, and attended local schools completing a B.S. at St. Francis Xavier University in 1973. He completed his Ph.D.in physics at the University of Toronto in 1978, working with S.H. Vosko on relativistic generalizations of density functional theory, and on the application of density functional theory to magnetism in metals.

## Research and career

Prior to joining the University of Texas, he worked at the Ottawa laboratory of the National Research Council Canada (1978–1987) and at Indiana University (1987–2000). He has held visiting positions at the Swiss Federal Institute of Technology in Zurich and the Max Planck Institute for Solid State Research in Stuttgart, Germany.
MacDonald's research has focused on new or unexplained phenomena related to the quantum physics of interacting electrons in materials. He has contributed to theories of the integer and fractional quantum Hall effects, spintronics in metals and semiconductors, topological Bloch bands and momentum-space Berry curvature phenomena, correlated electron-hole fluids and exciton and polariton condensates, and two-dimensional materials.
In 2011 MacDonald and Rafi Bistritzer, a former postdoctoral researcher in MacDonald's lab, predicted that it would be possible to realize strong correlation physics in graphene bilayers twisted to a magic relative orientation angle, foreshadowing the field of twistronics. Pablo Jarillo-Herrero, an experimentalist at Massachusetts Institute of Technology, found that the magic angle resulted in the unusual electrical properties the UT Austin scientists had predicted. At 1.1 degrees rotation at sufficiently low temperatures, electrons move from one layer to the other, creating a lattice and the phenomenon of superconductivity. The magic angle allows electric current to pass unimpeded, apparently without energy loss. This discovery could lead to more efficient electrical power transmission or new materials for quantum applications.
His recent work is focused on anticipating new physics in moiré superlattices, and on achieving a full understanding of magic-angle bilayer graphene and transition-metal dichalcogenide moiré superlattice systems.

## Honors and awards

MacDonald received the Canadian Association of Physicists's Herzberg Medal in 1987, the Oliver E. Buckley Prize of the American Physical Society in 2007 with James P. Eisenstein and Steven Girvin, the Ernst Mach Honorary Medal of the Czech Academy of Sciences in 2012, and the Wolf Prize in Physics in 2020 with Bistritzer and Jarrillo-Herrero. He was elected to the American Academy of Arts and Sciences in 2005 and the National Academy of the Sciences in 2010. He was named a 2024 Citation Laureate by Clarivate.

## Personal life

MacDonald is the second of eight children of David Roy (Jack) MacDonald and Elizabeth Jean (Betty) Sears. He grew up in Antigonish, Nova Scotia in the 1950s and 1960s, a town of 5000 people dominated at the time by 18th and 19th century Scottish and Irish immigrants. His namesake grandfather was a coal miner in New Waterford, N.S. and his mother was the daughter of a prominent local businessman and a graduate of Columbia University who wanted her children to be unafraid of the world 'from away.' MacDonald married Susan Wayling in Jimtown, Antigonish County, N.S. in 1974. They have two children, Erin (born 1977) and Brendan (born 1978) and four grandchildren living in Austin and San Francisco. Allan and Susan maintain a seasonal residence in Jimtown overlooking St. George's Bay - the backdrop of their summer days from youth to old age.

## Select publications

* MacDonald, AH; Vosko, SH (August 14, 1979). "A relativistic density functional formalism". Journal of Physics C: Solid State Physics. 12 (15): 2977. Bibcode:1979JPhC...12.2977M. doi:10.1088/0022-3719/12/15/007.
* MacDonald, AH; Picket, WE; Koelling, DD (May 20, 1980). "A linearised relativistic augmented-plane-wave method utilising approximate pure spin basis functions". Journal of Physics C: Solid State Physics. 13 (14): 2675. Bibcode:1980JPhC...13.2675M. doi:10.1088/0022-3719/13/14/009.
* Girvin, SM; MacDonald, Allan H; Platzman, PM (February 15, 1986). "Magneto-roton theory of collective excitations in the fractional quantum Hall effect". Physical Review B. 33 (4): 2481–2494. Bibcode:1986PhRvB..33.2481G. doi:10.1103/PhysRevB.33.2481. PMID 9938586.
* MacDonald, Allan H; Girvin, Steven M; Yoshioka, D (June 1, 1988). "t/U expansion for the Hubbard model". Physical Review B. 37 (16): 9753–9756. Bibcode:1988PhRvB..37.9753M. doi:10.1103/PhysRevB.37.9753. PMID 9944372.
* Moon, K; Mori, H; Yang, Kun; Girvin, SM; MacDonald, AH; Zheng, L; Yoshioka, D; Zhang, Shou-Cheng (February 15, 1995). "Spontaneous interlayer coherence in double-layer quantum Hall systems: Charged vortices and Kosterlitz-Thouless phase transitions". Physical Review B. 51 (8): 5138–5170. arXiv:cond-mat/9407031. Bibcode:1995PhRvB..51.5138M. doi:10.1103/PhysRevB.51.5138. PMID 9979391.
* Jungwirth, T; Niu, Q; MacDonald, Allan H (May 6, 2002). "Anomalous Hall effect in ferromagnetic semiconductors". Physical Review Letters. 88 (20): 207208. arXiv:cond-mat/0110484. Bibcode:2002PhRvL..88t7208J. doi:10.1103/PhysRevLett.88.207208. PMID 12005602.
* Yao, Yugui; Kleinman, Leonard; MacDonald, AH; Sinova, Jairo; Jungwirth, T; Wang, Ding-sheng; Wang, Enge; Niu, Qian (January 22, 2004). "First principles calculation of anomalous Hall conductivity in ferromagnetic bcc Fe". Physical Review Letters. 92 (3): 037204. arXiv:cond-mat/0307337. Bibcode:2004PhRvL..92c7204Y. doi:10.1103/PhysRevLett.92.037204. PMID 14753904.
* Eisenstein, JP; MacDonald, Allan H (December 9, 2004). "Bose–Einstein condensation of excitons in bilayer electron systems". Nature. 432 (7018): 691–694. arXiv:cond-mat/0404113. Bibcode:2004Natur.432..691E. doi:10.1038/nature03081. PMID 15592403.
* Nomura, Kentaro; MacDonald, Allan H. (June 28, 2006). "Quantum Hall ferromagnetism in graphene". Physical Review Letters. 96 (25): 256602. arXiv:cond-mat/0604113. Bibcode:2006PhRvL..96y6602N. doi:10.1103/PhysRevLett.96.256602. PMID 16907331.
* Zhang, Fan; Min, Hongki; Polini, Marco; MacDonald, AH (January 4, 2010). "Spontaneous inversion symmetry breaking in graphene bilayers". Physical Review B. 81 (4): 041402. Bibcode:2010PhRvB..81d1402Z. doi:10.1103/PhysRevB.81.041402.
* Bistritzer, Rafi; MacDonald, Allan H (July 5, 2011). "Moiré bands in twisted double-layer graphene". Proceedings of the National Academy of Sciences. 108 (30): 12233–12237. arXiv:1009.4203. Bibcode:2011PNAS..10812233B. doi:10.1073/pnas.1108174108. PMC 204362. PMID 3145708.
* Khanikaev, Alexander B; Mousavi, S Hossein; Tse, Wang-Kong; Kargarian, Mehdi; MacDonald, Allan H; Shvets, Gennady (December 16, 2012). "Photonic topological insulators". Nature Materials. 12 (3): 233–239. arXiv:1204.5700. doi:10.1038/nmat3520. PMID 23241532.
* Chen, Hua; Niu, Qian; MacDonald, Allan H (January 10, 2014). "Anomalous Hall effect arising from noncollinear antiferromagnetism". Physical Review Letters. 112 (1): 017205. arXiv:1309.4041. Bibcode:2014PhRvL.112a7205C. doi:10.1103/PhysRevLett.112.017205. PMID 24483927.
* Ji, Hengxing; Zhao, Xin; Qiao, Zhenhua; Jung, Jeil; Zhu, Yanwu; Lu, Yalin; Zhang, Li Li; MacDonald, Allan H.; Ruoff, Rodney S (February 21, 2014). "Capacitance of carbon-based electrical double-layer capacitors". Nature Communications. 5 (1): 3317. Bibcode:2014NatCo...5.3317J. doi:10.1038/ncomms4317. PMID 24557361.
* Wu, Fengcheng; Lovorn, Timothy; Tutuc, Emanuel; MacDonald, Allan H (July 10, 2018). "Hubbard model physics in transition metal dichalcogenide moiré bands". Physical Review Letters. 121 (2): 026402. arXiv:1804.03151. Bibcode:2018PhRvL.121b6402W. doi:10.1103/PhysRevLett.121.026402. PMID 30085734.
* Wu, Fengcheng; Lovorn, Timothy; Tutuc, Emanuel; Martin, Ivar; MacDonald, AH (February 28, 2019). "Topological insulators in twisted transition metal dichalcogenide homobilayers". Physical Review Letters. 122 (8): 086402. arXiv:1807.03311. Bibcode:2019PhRvL.122h6402W. doi:10.1103/PhysRevLett.122.086402. PMID 30932597.