David Neilson

B.Sc.(Hons) Melbourne, M.S., Ph.D. New York (Stony Brook)

Professor of Physics

reports and editor of review books.

Superfluidity in graphene multilayers... A new quantum phenomenon

in bilayers of graphene predicted by David Neilson and his co-workers

has been observed. In May 2018 Physical Review Letters published an

article by a University of Texas at Austin experimental group confirming a

theoretical prediction (Reference [30]) by David Neilson in collaboration

with Andrea Perali (University of Camerino) and Alexander Hamilton (University of New South Wales, Sydney) that

in a system of double bilayer graphene, and more generally in other semiconductors that can be made into

atomically thin flakes, quantum condensation and superfluid flow of condensed pairs of electrons and holes should

occur at low electron densities. This is a state of matter that had been searched for forty years, but not before

ground state of excitons in a double-layer semiconductor heterostructure should exist

over a wide range of readily attainable layer separations but larger than the separations typical in recent

experiments. This supersolid conforms with the original supersolid proposed as a phase of Helium-4 by Geoffrey

Chester, a solid with one particle per supersolid site. This makes it distinct from alternative supersolid versions

reported in cold-atom systems of a periodic density modulation or clustering of the superfluid.

The new phase appears at layer separations much smaller than the predicted exciton normal solid, and it persists

up to a solid--solid transition where the quantum phase coherence collapses. The ranges of layer separations and

exciton densities for the supersolid are within reach of current experimental capabilities.

Short Biography

Niels Bohr Institute in Copenhagen.

His doctoral project was on the Many Body Problem for the strongly interacting quantum system of electrons in

solids.

Obtaining his Ph.D. in 1974 he took an N.S.F. research Fellowship at Northwestern University in Chicago working

with Chia-Wei Woo on the quantum solidification of Helium and on the possibility of the solidification of nuclear

matter under the intense pressures found in neutron stars.

In 1975 he took up a position of Assistant Professor at the University of Southern California in Los Angeles.

From 1985-1994 he was Associate Professor, and from 1995 until 2003 Professor of Physics at New South

Research Associate with the National Enterprise for NanoScience and NanoTechnology (NEST) Centre at the Scuola

Normale Superiore in Pisa.

From 2018 to 2023 he was a Partner Investigator of the Australian Research Council Centre of Excellence "Future

Low Energy Electronic Transport" (FLEET) http://www.fleet.org.au/.

Since 2018 David Neilson has been Professor of Physics at the University of Antwerp.

Research Interests

David Neilson has wide experience in the field of semiconductor theory and has studied exotic quantum phases of

one- and two-dimensional systems found in semiconductor devices.

His recent work has been on superfluidity in graphene bilayer and double transition metal dichalcogenides (TMD)

monolayer devices.

without any heat-wasting resistance, in novel device

structures of atomically thin semiconductors.

Immediate application is for devices in the

computing and Artificial Intelligence industries.

These already use 8% of all electricity, a figure that is

doubling every 10 years.

The task is to develop new types of electronic

conduction without resistance in solid-state systems at room temperature. This would form the basis of a new type

of switching devices (transistors) with vastly lower energy consumption per computation than present silicon Si-

CMOS devices.

He developed comprehensive diagrammatic many-body calculations incorporating functional conserving

techniques for conduction electrons;

developed a quantum generalization of the classical glass equations with applications to conduction electrons,

extended it to include impurities in interacting electron 2D layers, and showed that this could lead to a transition to

a solid electron glass state;

has worked on ground state, localization and transport properties in disordered electron 2D systems;

has studied the effect of strong correlations between electron spins in electron systems at low density;

has studied the decisive effect that impurities have on the ground state of interacting electrons in quasi one-

dimensional quantum wires.

Research Grants from the Australian Research Council for an uninterrupted period of 25 years.

Organiser of international conferences including :

Multi-Condensate Superconductors and Superfluids in Solids and Ultracold Gases, Camerino 2014,

International Conference on Strongly Coupled Coulomb Systems, Camerino 2008,

International Conference on Novel Quantum Systems Italy 2005, International Conference on Soft Condensed Matter,

Sydney 2003,

International Workshop on Condensed Matter Theories Canberra 2002,

Australian Institute of Physics Biennial Congress, Sydney 2002.

Chair of Program Committee for International Conferences on Strongly Coupled Coulomb Systems, Camerino 2008,

Budapest 2011, Santa Fe 2014, Kiel 2017.

Chair of Eugene Feenberg Memorial Medal Committee for RPMBT-16 Bariloche 2011 and RPMBT-21 Chapel Hill North

Referee for international physics journals, including Physical Review Letters, Physical Review, Scientific Reports, Physics

Letters, Journal of Physics, Solid State Communications.

Examiner for external PhD theses.

Reviewer of grant applications for Research Council organisations in Australia (A.R.C.) Belgium, Canada (N.S.E.R.C.),

U.K. (S.E.R.C.), U.S.A. (N.S.F. and D.O.E.).

Fellow of the Australian Institute of Physics, member of the American Physical Society and the Institute of Physics

(U.K.).

Selected Publications

Representative examples of David Neilson's 150 publications

1. Density Collective Modes of Exciton Superfluidity in Bilayer Systems, Filippo Pascucci, Sara Conti, David

Andrea Perali, Jacques Tempere, David Neilson, Physical Review B 109 (9), 094512 (2024)

4. Dynamics of a superfluid and supersolid formed of dipolar excitons in bilayer semiconductors, Sara Conti,

David Neilson, Andrey Chaves, Luis A Peña Ardila, Milorad Milosevic, SUPERSTRIPES 2024, 80 (2024)

5. Intra-zero-energy Landau level crossings in bilayer graphene at high electric fields, Feixiang Xiang, Abhay

Gupta, Andrey Chaves, Zeb E Krix, Kenji Watanabe, Takashi Taniguchi, Michael S Fuhrer, François M Peeters,

David Neilson, Milorad V Miloevi, Alexander R Hamilton, Nano Letters 23 (21), 9683-9689 (2023)

6. Chester Supersolid of Spatially Indirect Excitons in Double-Layer Semiconductor Heterostructures, Sara

Conti, Andrea Perali, Alexander R. Hamilton, Milorad Miloevi, Francois Peeters, and David Neilson, Phys.

Rev. Lett. 130, 057001 (2023)

29. Excitonic superfluidity and screening in electron-hole bilayer systems, D. Neilson, A. Perali and A. R.

Hamilton,Phys. Rev. B Rapid Comm. 89, 060502(R) (2014)

30. High-Temperature Superfluidity in Double-Bilayer Graphene, A. Perali, D. Neilson and A. R. Hamilton, Phys.

Mod.Physics B 21, 2181 - 2190 (2007)

44. Effects of density imbalance on the BCS-BEC crossover in semiconductor electron-hole bilayers, P. Pieri, D.

Neilson, and G.C. Strinati, Phys. Rev. B 75, 113301 (2007)

47. Density dependence of critical magnetic fields at the metal-insulator bifurcation in two dimensions, D.J.W.

Geldart and D. Neilson, Phys. Rev. B 67, 045310 (2003)

48. Characterizing the metal-insulator transitions in 2D, D. Neilson, J.S. Thakur and E. Tosatti, Aust. J. Phys. 53, 531

Swierkowski, D.Neilson and J. Szymanski, Phys. Rev. B 53, 7923-7931 (1996)

63. Correlations in coupled layers of electrons and holes, (with J. Szymanski and L. Swierkowski), Phys. Rev. B 50,

11002 (1994)

66. Electron Liquids in Coupled Quantum Wells, (with L. Swierkowski and J. Szymanski), Acta Phys. Pol. 43, (1993)

67. Nonlocal exchange contribution to the Free Energy of inhomogeneous many-Fermion systems. III. Numerical

study for screened Coulomb interaction, (with M.R.A. Shegelski, D.J.W. Geldart and M.L. Glasser), Can. J.

1567 - 1571 (1986)

82. Dynamical Theory of Binary Ionic Mixtures, (with K.I. Golden and F.Green), Phys. Rev. A, Rapid Comm. 31,

3529 3532 (1985)

83. Functional Dependence of Electron Mobility on Distance of Remote Donor Impurities from the Interface in

AlGaAs/GaAs Heterostructures, (with J. Szymanski, F. Green, P.G. Kemeny and B.J. Linard), App. Surf. Sci. 22,

85. Nonlinear Response Function Approach to Binary Ionic Mixtures: Dynamical Theory, (with K.I. Golden and F.

Green), Phys. Rev. A 32, 1669 - 1692 (1985)

86. Bound Electron States of Coulombic Impurities and their Effect on Mobility in Inversion Layers, (with F. Green

and J. Szymanski), Surf. Sci. 142, 279 - 283 (1984)

101. Electron Correlations at Metallic Densities, (with G.E. Brown), Phys. Rev. B 12, 2138 - 2149 (1975)

102. Positron Annihilation and Electron Correlations in Metals, (with A.D. Jackson), Phys. Rev. B 12, 1689 -