Anupam Garg

Anupam Garg
Born (1956-08-17) 17 August 1956 (age 68)
Amritsar, India
Alma mater
Known forLeggett–Garg inequality
Scientific career
FieldsPhysics
InstitutionsNorthwestern University
Doctoral advisorN. David Mermin[1]

Anupam Garg is a professor in the department of Physics & Astronomy at Northwestern University, Illinois. He was born on August 17, 1956 in Amritsar, India. He received a Master's degree from IIT Delhi in 1977, and a Ph.D. in 1983 from Cornell University. In 2012, he became a Fellow of the American Physical Society thanks to his work on molecular magnetism and macroscopic quantum phenomena.

Garg is best known for formulating the Leggett–Garg inequality, named for Anthony James Leggett and himself, which is a mathematical inequality fulfilled by all macrorealistic physical theories.[2] He is also known for the Garg-Onuchic-Ambegaokar model of charge transfer. [3] In addition, he discovered the phenomenon of topological quenching of the tunnel splitting in a toy Hamiltonian for spin tunneling, [4] that was subsequently found experimentally in the magnetic molecule Fe8. [5]

Garg's initial work on spin tunnelling was based on an early and incomplete understanding of spin path integrals, and the experiments on Fe8 led him to an extensive study of the larger field of coherent state path integrals, especially as they pertain to quantum and semi-classical phenomena associated with the orientation of quantum mechanical spin. With his collaborators, Garg has made several original contributions to this field: (1) It was discovered that there is a global anomaly in the integral over the fluctuations around the classical path, whose resolution was also discovered. [6] (2) The experiments on Fe8 did not agree with the initial theoretical predictions in details such as the locations and the number of quenching points. These discrepancies were completely resolved by the discovery that it was necessary to include classical paths with discontinuities at their end points. [7]

Garg is the author of a graduate physics textbook, Classical Electromagnetism in a Nutshell,[8] and an undergraduate text, Mathematics with a Scientific Sensibility. [9]

  1. ^ "Anupam Garg". Physics Tree.
  2. ^ Leggett, A. J.; Garg, Anupam (1985-03-04). "Quantum mechanics versus macroscopic realism: Is the flux there when nobody looks?" (PDF). Physical Review Letters. 54 (9). American Physical Society (APS): 857–860. Bibcode:1985PhRvL..54..857L. doi:10.1103/physrevlett.54.857. ISSN 0031-9007. PMID 10031639.
  3. ^ Garg, Anupam; Onuchic, José Nelson; Ambegaokar, Vinay (1985). "Effect of friction on electron transfer in biomolecules". The Journal of Chemical Physics. 83 (9). AIP Publishing: 4491–4503. Bibcode:1985JChPh..83.4491G. doi:10.1063/1.449017. ISSN 0021-9606.
  4. ^ Garg, Anupam (1993). "Topologically quenched tunnel splitting in spin systems without Kramers' degeneracy". Europhysics Letters. 22 (3). IOP Publishing: 205–210. doi:10.1209/0295-5075/22/3/008.
  5. ^ Wernesdorfer, Wolfgang; Sessoli, Roberta (1999). "Quantum Phase Interference and Parity Effects in Magnetic Molecular Clusters". Science. 284: 133.
  6. ^ Stone, Michael; Park, Kee-Su; Garg, Anupam (2000). "The semiclassical propagator for spin coherent states". Journal of Mathematical Physics. 41: 8025.
  7. ^ Kececio˘glu, Ersin; Garg, Anupam (2002). "SU(2) Instantons with Boundary Jumps and Spin Tunneling in Magnetic Molecules". Physical Review Letters. 88: 237205.
  8. ^ Princeton University Press (2012).
  9. ^ "Mathematics with a Scientific Sensibility".