TY - JOUR
T1 - Low-noise phase of a two-dimensional active nematic system
AU - Shankar, Suraj
AU - Ramaswamy, Sriram
AU - Marchetti, M. Cristina
N1 - Funding Information:
We thank M. Barma for useful discussions. This work was supported by the National Science Foundation at Syracuse University through Awards No. DMR-1609208 (M.C.M., S.S.) and No. DGE-1068780 (M.C.M.) and at KITP under the Grant No. NSF PHY-1125915. S.S. and M.C.M. thank the KITP for its hospitality during the completion of some of the work and the Syracuse Soft & Living Matter Program for support. S.R. was supported by a J. C. Bose Fellowship of the SERB, Government of India, and a Homi Bhabha Chair Professorship of the Tata Education and Development Trust.
Publisher Copyright:
© 2018 American Physical Society.
PY - 2018/1/29
Y1 - 2018/1/29
N2 - We consider a collection of self-driven apolar particles on a substrate that organize into an active nematic phase at sufficiently high density or low noise. Using the dynamical renormalization group, we systematically study the two-dimensional fluctuating ordered phase in a coarse-grained hydrodynamic description involving both the nematic director and the conserved density field. In the presence of noise, we show that the system always displays only quasi-long-ranged orientational order beyond a crossover scale. A careful analysis of the nonlinearities permitted by symmetry reveals that activity is dangerously irrelevant over the linearized description, allowing giant number fluctuations to persist although now with strong finite-size effects and a nonuniversal scaling exponent. Nonlinear effects from the active currents lead to power-law correlations in the density field, thereby preventing macroscopic phase separation in the thermodynamic limit.
AB - We consider a collection of self-driven apolar particles on a substrate that organize into an active nematic phase at sufficiently high density or low noise. Using the dynamical renormalization group, we systematically study the two-dimensional fluctuating ordered phase in a coarse-grained hydrodynamic description involving both the nematic director and the conserved density field. In the presence of noise, we show that the system always displays only quasi-long-ranged orientational order beyond a crossover scale. A careful analysis of the nonlinearities permitted by symmetry reveals that activity is dangerously irrelevant over the linearized description, allowing giant number fluctuations to persist although now with strong finite-size effects and a nonuniversal scaling exponent. Nonlinear effects from the active currents lead to power-law correlations in the density field, thereby preventing macroscopic phase separation in the thermodynamic limit.
UR - http://www.scopus.com/inward/record.url?scp=85041589755&partnerID=8YFLogxK
UR - http://www.scopus.com/inward/citedby.url?scp=85041589755&partnerID=8YFLogxK
U2 - 10.1103/PhysRevE.97.012707
DO - 10.1103/PhysRevE.97.012707
M3 - Article
AN - SCOPUS:85041589755
SN - 1063-651X
VL - 97
JO - Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
JF - Physical Review E - Statistical Physics, Plasmas, Fluids, and Related Interdisciplinary Topics
IS - 1
M1 - 012707
ER -