Because of injuries sustained in a childhood accident, Jain walks with the aid of a prosthesis.[3][4] After being awarded theWolf Prize in Physics, he recounted his journey as: “Looking back, it is hard to believe how incredibly fortunate I have been. Growing up in a poor village in India, traumatized by an accident that left me on crutches with a lifelong disability, I did not think I would ever walk again or attend college, let alone pursue my dream of becoming a physicist.”[8] He creditsJaipur Foot with enabling him to continue education.[3]
Jain predicted that when two-dimensional electrons are subjected to a large magnetic field, they dress themselves with an even number of quantized vortices to form emergent particles termedcomposite fermions.[9] Composite fermions are pictured as electrons dressed with magnetic flux quanta, and are predicted to experience a substantially reduced magnetic field. Thus, the strongly correlated 2D electrons in a high magnetic field become weakly interacting composite fermions at a reduced magnetic field. Composite fermions correctly predict the rich phenomenology of this system originating from a variety of strongly correlated states of electrons, including the fractional quantum Hall states, the Fermi-liquid like metallic states, superconductor-like paired states, and crystal states.[10][11][12][13][14]
Jain theorized that the integer quantum Hall effect of composite fermions carrying 2p flux quanta shows as the fractional quantum Hall effect of electrons at fractions n/(2pn±1), where n and p are integers. These fractions, along with their hole partners 1 - n/(2pn±1), termed the Jain sequences, account for nearly all known fractional quantum Hall states, called the Jain states. Experimental evidence has been reported for four species of composite fermions, those with 2, 4, 6, and 8 flux quanta attached.[15][16][17]
Jain also constructed ansatz wave functions[9] for the fractional quantum Hall states, which were shown by him and his collaborators to be extremely accurate.[18][19][20] They demonstrated that the excited composite fermions, also called "quasiparticles", exhibit fractional charge and anyon statistics.[21] They generalized the composite-fermion framework to include the spin (or valley) degree of freedom[22][23][24] and to bilayers,[25] and successfully predicted the phase diagram of composite-fermion crystals.[26][27] They further showed that the residual interactions among composite fermions can cause pairing of composite fermions at even-denominator fractions in higher Landau levels,[28] in wide quantum wells,[29] or with large Landau-level mixing.[30] They examined the fractional quantum Hall effect of composite fermions to explain fractions such as 4/11 and 5/13.[31]
Jain also is the originator the "parton" construction,[32] which generates candidate fractional quantum Hall states beyond the Jain sequences and includes some of the earliest proposed non-Abelian states.[33] Several parton states beyond the standard Jain states have been shown to be experimentally relevant.[34][35]
Oliver E. Buckley Prize awarded by theAmerican Physical Society for a most important contribution to the advancement of knowledge in Condensed Matter Physics, 2002, along withNicholas Read andRobert Willett.[36] Citation: "For theoretical and experimental work establishing the composite fermion model for the half-filled Landau level and other quantized Hall systems"
Elected member ofAmerican Academy of Arts and Sciences, 2008.[37] Citation: "Evan Pugh University Professor and Erwin W. Mueller Professor of Physics. Predicted that electrons in the factional quantum Hall effect regime capture quantized vortices to form new particles, which he named composite fermions. Subsequently observed, composite fermions brought clarity to the subject and spawned new lines of theoretical inquiries and elegant new experiments."
Elected Foreign Fellow of theIndian National Science Academy, 2025.[40] Citation: "Prof Jain predicted a new class of exotic particles, which he named “composite fermions,” and explained the fractional quantum Hall effect as the integer quantum Hall effect of composite fermions. In doing so, he accomplished a unification of the fractional and the integer quantum Hall effects, two Nobel prize winning phenomena. His discovery of composite fermions is recognized as a singular and transformative development in the realm of condensed matter physics."
