Allan H. MacDonald (born December 1, 1951) is a theoreticalcondensed matter physicist and the Sid W. Richardson Foundation Regents Chair Professor of Physics atThe University of Texas at Austin.[1][2][3][4] His research interests are centered on the electronic properties of electrons in metals and semiconductors.[5] He is well known for his work on correlated many-electron states in low-dimensional systems.[6] In 2020, he became one of the laureates of theWolf Prize in Physics, for predicting the magic angle that turns twistedbilayer graphene into asuperconductor.[3][7]
He was born inAntigonish, Nova Scotia, Canada, and attended local schools completing a B.S. at St. Francis Xavier University in 1973.[2][3] He completed his Ph.D.in physics at theUniversity of Toronto in 1978, working withS.H. Vosko on relativistic generalizations ofdensity functional theory, and on the application of density functional theory to magnetism in metals.[3]
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 andfractional quantum Hall effects,spintronics in metals and semiconductors, topological Bloch bands and momentum-spaceBerry curvature phenomena, correlated electron-hole fluids andexciton andpolariton condensates, andtwo-dimensional materials.
In 2011 MacDonald andRafi Bistritzer, a former postdoctoral researcher in MacDonald's lab, predicted that it would be possible to realize strong correlation physics ingraphene bilayers twisted to a magic relative orientation angle,[8][9] foreshadowing the field oftwistronics.[10]Pablo Jarillo-Herrero, an experimentalist atMassachusetts Institute of Technology, found that the magic angle resulted in the unusual electrical properties the UT Austin scientists had predicted.[11] At 1.1 degrees rotation at sufficiently low temperatures, electrons move from one layer to the other, creating a lattice and the phenomenon ofsuperconductivity. The magic angle allows electric current to pass unimpeded, apparently without energy loss. This discovery could lead to more efficientelectrical power transmission or new materials for quantum applications.[12]
His recent work is focused on anticipating new physics inmoiré superlattices, and on achieving a full understanding of magic-angle bilayer graphene andtransition-metal dichalcogenide moiré superlattice systems.
MacDonald is the second of eight children of David Roy (Jack) MacDonald and Elizabeth Jean (Betty) Sears. He grew up inAntigonish, 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.
