@article{5794,
  abstract     = {We present an approach to interacting quantum many-body systems based on the notion of quantum groups, also known as q-deformed Lie algebras. In particular, we show that, if the symmetry of a free quantum particle corresponds to a Lie group G, in the presence of a many-body environment this particle can be described by a deformed group, Gq. Crucially, the single deformation parameter, q, contains all the information about the many-particle interactions in the system. We exemplify our approach by considering a quantum rotor interacting with a bath of bosons, and demonstrate that extracting the value of q from closed-form solutions in the perturbative regime allows one to predict the behavior of the system for arbitrary values of the impurity-bath coupling strength, in good agreement with nonperturbative calculations. Furthermore, the value of the deformation parameter allows one to predict at which coupling strengths rotor-bath interactions result in a formation of a stable quasiparticle. The approach based on quantum groups does not only allow for a drastic simplification of impurity problems, but also provides valuable insights into hidden symmetries of interacting many-particle systems.},
  author       = {Yakaboylu, Enderalp and Shkolnikov, Mikhail and Lemeshko, Mikhail},
  issn         = {00319007},
  journal      = {Physical Review Letters},
  number       = {25},
  publisher    = {American Physical Society},
  title        = {{Quantum groups as hidden symmetries of quantum impurities}},
  doi          = {10.1103/PhysRevLett.121.255302},
  volume       = {121},
  year         = {2018},
}

@article{9014,
  abstract     = {In this Letter, we explore experimentally the phase behavior of a dense active suspension of self-propelled colloids. In addition to a solidlike and gaslike phase observed for high and low densities, a novel cluster phase is reported at intermediate densities. This takes the form of a stationary assembly of dense aggregates—resulting from a permanent dynamical merging and separation of active colloids—whose average size grows with activity as a linear function of the self-propelling velocity. While different possible scenarios can be considered to account for these observations—such as a generic velocity weakening instability recently put forward—we show that the experimental results are reproduced mathematically by a chemotactic aggregation mechanism, originally introduced to account for bacterial aggregation and accounting here for diffusiophoretic chemical interaction between colloidal swimmers.},
  author       = {Theurkauff, I. and Cottin-Bizonne, C. and Palacci, Jérémie A and Ybert, C. and Bocquet, L.},
  issn         = {10797114},
  journal      = {Physical Review Letters},
  number       = {26},
  publisher    = {American Physical Society },
  title        = {{Dynamic clustering in active colloidal suspensions with chemical signaling}},
  doi          = {10.1103/physrevlett.108.268303},
  volume       = {108},
  year         = {2012},
}

@article{9012,
  abstract     = {In this Letter, we characterize experimentally the diffusiophoretic motion of colloids and λ-DNA toward higher concentration of solutes, using microfluidic technology to build spatially and temporally controlled concentration gradients. We then demonstrate that segregation and spatial patterning of the particles can be achieved from temporal variations of the solute concentration profile. This segregation takes the form of a strong trapping potential, stemming from an osmotically induced rectification mechanism of the solute time-dependent variations. Depending on the spatial and temporal symmetry of the solute signal, localization patterns with various shapes can be achieved. These results highlight the role of solute contrasts in out-of-equilibrium processes occurring in soft matter.},
  author       = {Palacci, Jérémie A and Abécassis, Benjamin and Cottin-Bizonne, Cécile and Ybert, Christophe and Bocquet, Lydéric},
  issn         = {10797114},
  journal      = {Physical Review Letters},
  number       = {13},
  publisher    = {American Physical Society},
  title        = {{Colloidal motility and pattern formation under rectified diffusiophoresis}},
  doi          = {10.1103/physrevlett.104.138302},
  volume       = {104},
  year         = {2010},
}

@article{9013,
  abstract     = {In this Letter, we investigate experimentally the nonequilibrium steady state of an active colloidal suspension under gravity field. The active particles are made of chemically powered colloids, showing self propulsion in the presence of an added fuel, here hydrogen peroxide. The active suspension is studied in a dedicated microfluidic device, made of permeable gel microstructures. Both the microdynamics of individual colloids and the global stationary state of the suspension under gravity are measured with optical microscopy. This yields a direct measurement of the effective temperature of the active system as a function of the particle activity, on the basis of the fluctuation-dissipation relationship. Our work is a first step in the experimental exploration of the out-of-equilibrium properties of active colloidal systems.},
  author       = {Palacci, Jérémie A and Cottin-Bizonne, Cécile and Ybert, Christophe and Bocquet, Lydéric},
  issn         = {10797114},
  journal      = {Physical Review Letters},
  number       = {8},
  publisher    = {American Physical Society },
  title        = {{Sedimentation and effective temperature of active colloidal suspensions}},
  doi          = {10.1103/physrevlett.105.088304},
  volume       = {105},
  year         = {2010},
}