Nonequilibrium forces following quenches in active and thermal matter
Nonequilibrium systems with conserved quantities like density or momentum are known to exhibit long-ranged correlations. This, in turn, leads to long-ranged fluctuation-induced (Casimir) forces, predicted to arise in a variety of nonequilibrium settings. Here, we study such forces, which arise trans...
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| Format: | Article |
| Language: | English |
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American Physical Society
2018
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| Online Access: | http://hdl.handle.net/1721.1/114655 https://orcid.org/0000-0002-1112-5912 |
| _version_ | 1826209248125648896 |
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| author | Rohwer, Christian M. Solon, Alexandre Kardar, Mehran Krüger, Matthias |
| author2 | Massachusetts Institute of Technology. Department of Physics |
| author_facet | Massachusetts Institute of Technology. Department of Physics Rohwer, Christian M. Solon, Alexandre Kardar, Mehran Krüger, Matthias |
| author_sort | Rohwer, Christian M. |
| collection | MIT |
| description | Nonequilibrium systems with conserved quantities like density or momentum are known to exhibit long-ranged correlations. This, in turn, leads to long-ranged fluctuation-induced (Casimir) forces, predicted to arise in a variety of nonequilibrium settings. Here, we study such forces, which arise transiently between parallel plates or compact inclusions in a gas of particles, following a change (“quench”) in temperature or activity of the medium. Analytical calculations, as well as numerical simulations of passive or active Brownian particles, indicate two distinct forces: (i) The immediate effect of the quench is adsorption or desorption of particles of the medium to the immersed objects, which in turn initiates a front of relaxing (mean) density. This leads to time-dependent density-induced forces. (ii) A long-term effect of the quench is that density fluctuations are modified, manifested as transient (long-ranged) (pair-)correlations that relax diffusively to their (short-ranged) steady-state limit. As a result, transient fluctuation-induced forces emerge. We discuss the properties of fluctuation-induced and density-induced forces as regards universality, relaxation as a function of time, and scaling with distance between objects. Their distinct signatures allow us to distinguish the two types of forces in simulation data. Our simulations also show that a quench of the effective temperature of an active medium gives rise to qualitatively similar effects to a temperature quench in a passive medium. Based on this insight, we propose several scenarios for the experimental observation of the forces described here. |
| first_indexed | 2024-09-23T14:19:31Z |
| format | Article |
| id | mit-1721.1/114655 |
| institution | Massachusetts Institute of Technology |
| language | English |
| last_indexed | 2024-09-23T14:19:31Z |
| publishDate | 2018 |
| publisher | American Physical Society |
| record_format | dspace |
| spelling | mit-1721.1/1146552022-10-01T20:38:15Z Nonequilibrium forces following quenches in active and thermal matter Rohwer, Christian M. Solon, Alexandre Kardar, Mehran Krüger, Matthias Massachusetts Institute of Technology. Department of Physics Solon, Alexandre Kardar, Mehran Nonequilibrium systems with conserved quantities like density or momentum are known to exhibit long-ranged correlations. This, in turn, leads to long-ranged fluctuation-induced (Casimir) forces, predicted to arise in a variety of nonequilibrium settings. Here, we study such forces, which arise transiently between parallel plates or compact inclusions in a gas of particles, following a change (“quench”) in temperature or activity of the medium. Analytical calculations, as well as numerical simulations of passive or active Brownian particles, indicate two distinct forces: (i) The immediate effect of the quench is adsorption or desorption of particles of the medium to the immersed objects, which in turn initiates a front of relaxing (mean) density. This leads to time-dependent density-induced forces. (ii) A long-term effect of the quench is that density fluctuations are modified, manifested as transient (long-ranged) (pair-)correlations that relax diffusively to their (short-ranged) steady-state limit. As a result, transient fluctuation-induced forces emerge. We discuss the properties of fluctuation-induced and density-induced forces as regards universality, relaxation as a function of time, and scaling with distance between objects. Their distinct signatures allow us to distinguish the two types of forces in simulation data. Our simulations also show that a quench of the effective temperature of an active medium gives rise to qualitatively similar effects to a temperature quench in a passive medium. Based on this insight, we propose several scenarios for the experimental observation of the forces described here. National Science Foundation (U.S.) (Grant DMR-1708280) 2018-04-10T19:53:40Z 2018-04-10T19:53:40Z 2018-03 2018-02 2018-03-20T18:00:16Z Article http://purl.org/eprint/type/JournalArticle 2470-0045 2470-0053 http://hdl.handle.net/1721.1/114655 Rohwer, Christian M. et al. "Nonequilibrium forces following quenches in active and thermal matter." Physical Review E 97, 3 (March 2018): 032125 © 2018 American Physical Society https://orcid.org/0000-0002-1112-5912 en http://dx.doi.org/10.1103/PhysRevE.97.032125 Physical Review E Article is made available in accordance with the publisher's policy and may be subject to US copyright law. Please refer to the publisher's site for terms of use. American Physical Society application/pdf American Physical Society American Physical Society |
| spellingShingle | Rohwer, Christian M. Solon, Alexandre Kardar, Mehran Krüger, Matthias Nonequilibrium forces following quenches in active and thermal matter |
| title | Nonequilibrium forces following quenches in active and thermal matter |
| title_full | Nonequilibrium forces following quenches in active and thermal matter |
| title_fullStr | Nonequilibrium forces following quenches in active and thermal matter |
| title_full_unstemmed | Nonequilibrium forces following quenches in active and thermal matter |
| title_short | Nonequilibrium forces following quenches in active and thermal matter |
| title_sort | nonequilibrium forces following quenches in active and thermal matter |
| url | http://hdl.handle.net/1721.1/114655 https://orcid.org/0000-0002-1112-5912 |
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