David Nelson
Collective effects in the physics and chemistry of condensed matter

Our laboratory is interested in the interplay between fluctuations, geometry and statistical mechanics. In collaboration with Harvard colleague Bertrand I. Halperin, we developed a theory of dislocation-mediated melting in two dimensions, a key prediction of which (a fourth “hexatic” phase of matter, interposed between the usual solid and liquid phases) has now been confirmed. Other research interests includes a theory of the structure and statistical mechanics of metallic glasses; “tethered surfaces”, which are two-dimensional generalizations of linear polymer chains having a “fishnet-like” structure; flux line entanglement in new, high temperature-superconductors; vortex physics; the statistical mechanics of polymers; topological defects on frozen topographies; and biophysics. In the latter area, we are particularly interested in two areas: modeling the architecture of virus capsids and modeling the unzipping of nucleic acid strands in duplex DNA and complex RNA secondary structures.

Publications:
Kafri, Y., Lubensky, D.K. and Nelson, D.R. 2004. Dynamics of molecular motors and polymer translocation with sequence heterogeneity. Biophys. J. 86: 3373-3391.

Lenz, P. and Nelson, D.R. 2003. Hexatic undulations in curved geometries. Phys Rev E Stat. Nonlin Soft Matter Phys. 67: 031502.

Lubensky, D. and Nelson, D.R. 2002. Single molecule statistics and the polynucleotide unzipping transition. Phys. Rev. E 65: 03917.

Jain, S. and Nelson, D.R. 2000. Statistical mechanics of vacancy and interstitial strings in hexagonal columnar crystals. Phys. Rev. E Stat. Phys. Plasmas Fluids. 61: 1599-1615.