News Items

Research Highlight (See all of our publications)

Composite Dislocations in Smectic Liquid Crystals,
Phys. Rev. Lett. 118 (2017) 2578016
, by Hillel Aharoni, Thomas Machon, and Randall D. Kamien

Smectic liquid crystals are charcterized by layers that have a preferred uniform spacing and vanishing curvature in their ground state. Dislocations in the smectics play an important role in phase nucleation, layer reorientation, and dynamics. Typically modeled as possessing one line singularity, the layer structure of a dislocation leads to a diverging compression strain as one approaches the defect center, suggesting a large, elastically determined melted core. However, it has been observed that for large charge dislocations, the defect breaks up into two disclinations [C. E. Williams, Philos. Mag. 32, 313 (1975)]. Here we investigate the topology of the composite core. Because the smectic cannot twist, transformations between different disclination geometries are highly constrained. We demonstrate the geometric route between them and show that despite enjoying precisely the topological rules of the three-dimensional nematic, the additional structure of line disclinations in three-dimensional smectics localizes transitions to higher-order point singularities.

General News

  • Lisa Tran takes fifth place in Nikon Small World in Motion Competition! (September 2017)

  • Tom Machon accepts faculty position at University of Bristol! (July 2017)

  • Lisa Tran awarded American Association of University Women Dissertation Fellowship! (May 2017)

  • Former Postdoc Mohamed Gharbi accepts faculty position at UMass Boston! (May 2017)

  • Former student Carl Modes accepts Research Group Leader Position at MPI Dresden! (April 2017)

  • Max Lavrentovich accepts faculty position at University of Tennessee Knoxville! (April 2017)

  • Lisa Tran receives Dissertation Completion Award from the School of Arts and Sciences! (March 2017)

  • Graduate Student Lisa Tran chosen as GSNP Student Award Finalist. (December 2016)

  • Ex-Postdoc Chris Santangelo wins 2017 GSOFT Early Career Award For seminal theoretical contributions exploiting geometry and topology to understand the elasticity of soft materials. (October 2016)

  • Daniel Beller wins 2016 Glenn Brown Dissertation Prize of the International Liquid Crystal Society For his outstanding theoretical work to identify the rich possibilities and outcomes of controlling defects in nematic and smectic liquid crystals under a variety of boundary conditions. The demonstration of the well controlled disclinations and focal conics is expected to open up a novel route for self-assembly in soft-ordered materials . (June 2016)

  • Tom Machon arrives from England. Welcome! (May 2016)

  • Sabetta Matsumoto accepts faculty position at Georgia Tech! (May 2016)

  • Francesca Serra accepts faculty position at Johns Hopkins University! (March 2016)

  • Randy Kamien awarded G.W. Gray Medal of the British Liquid Crystal Society. (February 2016)

  • Hillel Aharoni arrives from Jerusalem. Welcome! (August 2015)

  • Tingting Gong chosen as Apker Award Finalist! (July 2015)

  • Tingting Gong chosen as 2015 Dean's Scholar! (January 2015)

  • Max Lavrentovich arrives from Cambridge, MA. Welcome! (September 2014)

  • Daniel Sussman receives American Philosophical Society Post-Doctoral Fellowship in Advanced Materials! (June 2014)

  • Tingting Gong chosen as a Vagelos Challenge Awardee! (May 2014)

  • Ex-postdoc Simon Čopar wins 2014 Glenn Brown Dissertation Prize of the International Liquid Crystal Society For his outstanding thesis describing a new theoretical approach, whereby the combination of local defect geometry and topological properties of nematic disclinations networks allows for a complete theoretical description of arbitrary complex nematic braids. (May 2014)

  • Daniel Beller succesfully defends thesis. Hurray! (April 2014)

  • Ex-postdoc Gareth Alexander awarded British Liquid Crystal Society Young Scientist Award. (April 2014)

  • Toen Castle arrives from down under. Welcome! (March 2014)

  • Dan Beller has been awarded the George F. Carrier fellowship in Harvard's School of Engineering and Applied Science, an endowed honorific postdoctoral position in widely applied mathematics. (February 2014)

  • Dan Beller accepts postdoctoral position at Harvard University. (January 2014)

  • Dan Beller awarded 2013 Eli Burstein Prize for "his deep understanding of the geometry of focal domains in liquid crystals leading to novel devices and the exquisite control of topology and topography." (August 2013)

  • Randy Kamien appointed Simons Investigator. (May 2013)

  • Daniel Beller awarded 2013 Teece Fellowship for dissertation research! (April 2013)

See our news archive.

Talks and Presentations

Upcoming talks:
Last Modified 22 September 2017