@article{18190, abstract = {Strongly correlated systems can exhibit unexpected phenomena when brought in a state far from equilibrium. An example is many-body localization, which prevents generic interacting systems from reaching thermal equilibrium even at long times1,2. The stability of the many-body localized phase has been predicted to be hindered by the presence of small thermal inclusions that act as a bath, leading to the delocalization of the entire system through an avalanche propagation mechanism3,4,5,6,7,8. Here we study the dynamics of a thermal inclusion of variable size when it is coupled to a many-body localized system. We find evidence for accelerated transport of thermal inclusion into the localized region. We monitor how the avalanche spreads through the localized system and thermalizes it site by site by measuring the site-resolved entropy over time. Furthermore, we isolate the strongly correlated bath-induced dynamics with multipoint correlations between the bath and the system. Our results have implications on the robustness of many-body localized systems and their critical behaviour.}, author = {Leonard, Julian and Kim, Sooshin and Rispoli, Matthew and Lukin, Alexander and Schittko, Robert and Kwan, Joyce and Demler, Eugene and Sels, Dries and Greiner, Markus}, issn = {1745-2481}, journal = {Nature Physics}, number = {4}, pages = {481--485}, publisher = {Springer Nature}, title = {{Probing the onset of quantum avalanches in a many-body localized system}}, doi = {10.1038/s41567-022-01887-3}, volume = {19}, year = {2023}, } @article{12837, abstract = {As developing tissues grow in size and undergo morphogenetic changes, their material properties may be altered. Such changes result from tension dynamics at cell contacts or cellular jamming. Yet, in many cases, the cellular mechanisms controlling the physical state of growing tissues are unclear. We found that at early developmental stages, the epithelium in the developing mouse spinal cord maintains both high junctional tension and high fluidity. This is achieved via a mechanism in which interkinetic nuclear movements generate cell area dynamics that drive extensive cell rearrangements. Over time, the cell proliferation rate declines, effectively solidifying the tissue. Thus, unlike well-studied jamming transitions, the solidification uncovered here resembles a glass transition that depends on the dynamical stresses generated by proliferation and differentiation. Our finding that the fluidity of developing epithelia is linked to interkinetic nuclear movements and the dynamics of growth is likely to be relevant to multiple developing tissues.}, author = {Bocanegra, Laura and Singh, Amrita and Hannezo, Edouard B and Zagórski, Marcin P and Kicheva, Anna}, issn = {1745-2481}, journal = {Nature Physics}, pages = {1050--1058}, publisher = {Springer Nature}, title = {{Cell cycle dynamics control fluidity of the developing mouse neuroepithelium}}, doi = {10.1038/s41567-023-01977-w}, volume = {19}, year = {2023}, } @article{14032, abstract = {Arrays of Josephson junctions are governed by a competition between superconductivity and repulsive Coulomb interactions, and are expected to exhibit diverging low-temperature resistance when interactions exceed a critical level. Here we report a study of the transport and microwave response of Josephson arrays with interactions exceeding this level. Contrary to expectations, we observe that the array resistance drops dramatically as the temperature is decreased—reminiscent of superconducting behaviour—and then saturates at low temperature. Applying a magnetic field, we eventually observe a transition to a highly resistive regime. These observations can be understood within a theoretical picture that accounts for the effect of thermal fluctuations on the insulating phase. On the basis of the agreement between experiment and theory, we suggest that apparent superconductivity in our Josephson arrays arises from melting the zero-temperature insulator.}, author = {Mukhopadhyay, Soham and Senior, Jorden L and Saez Mollejo, Jaime and Puglia, Denise and Zemlicka, Martin and Fink, Johannes M and Higginbotham, Andrew P}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {General Physics and Astronomy}, pages = {1630--1635}, publisher = {Springer Nature}, title = {{Superconductivity from a melted insulator in Josephson junction arrays}}, doi = {10.1038/s41567-023-02161-w}, volume = {19}, year = {2023}, } @article{12209, abstract = {Embryo development requires biochemical signalling to generate patterns of cell fates and active mechanical forces to drive tissue shape changes. However, how these processes are coordinated, and how tissue patterning is preserved despite the cellular flows occurring during morphogenesis, remains poorly understood. Gastrulation is a crucial embryonic stage that involves both patterning and internalization of the mesendoderm germ layer tissue. Here we show that, in zebrafish embryos, a gradient in Nodal signalling orchestrates pattern-preserving internalization movements by triggering a motility-driven unjamming transition. In addition to its role as a morphogen determining embryo patterning, graded Nodal signalling mechanically subdivides the mesendoderm into a small fraction of highly protrusive leader cells, able to autonomously internalize via local unjamming, and less protrusive followers, which need to be pulled inwards by the leaders. The Nodal gradient further enforces a code of preferential adhesion coupling leaders to their immediate followers, resulting in a collective and ordered mode of internalization that preserves mesendoderm patterning. Integrating this dual mechanical role of Nodal signalling into minimal active particle simulations quantitatively predicts both physiological and experimentally perturbed internalization movements. This provides a quantitative framework for how a morphogen-encoded unjamming transition can bidirectionally couple tissue mechanics with patterning during complex three-dimensional morphogenesis.}, author = {Nunes Pinheiro, Diana C and Kardos, Roland and Hannezo, Edouard B and Heisenberg, Carl-Philipp J}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {General Physics and Astronomy}, number = {12}, pages = {1482--1493}, publisher = {Springer Nature}, title = {{Morphogen gradient orchestrates pattern-preserving tissue morphogenesis via motility-driven unjamming}}, doi = {10.1038/s41567-022-01787-6}, volume = {18}, year = {2022}, } @article{10589, abstract = {Superconducting devices ubiquitously have an excess of broken Cooper pairs, which can hamper their performance. It is widely believed that external radiation is responsible but a study now suggests there must be an additional, unknown source.}, author = {Higginbotham, Andrew P}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {superconducting devices, superconducting properties and materials}, pages = {126}, publisher = {Springer Nature}, title = {{A secret source}}, doi = {10.1038/s41567-021-01459-x}, volume = {18}, year = {2022}, } @article{19909, abstract = {Most water in the Universe may be superionic, and its thermodynamic and transport properties are crucial for planetary science but difficult to probe experimentally or theoretically. We use machine learning and free-energy methods to overcome the limitations of quantum mechanical simulations and characterize hydrogen diffusion, superionic transitions and phase behaviours of water at extreme conditions. We predict that close-packed superionic phases, which have a fraction of mixed stacking for finite systems, are stable over a wide temperature and pressure range, whereas a body-centred cubic superionic phase is only thermodynamically stable in a small window but is kinetically favoured. Our phase boundaries, which are consistent with existing—albeit scarce—experimental observations, help resolve the fractions of insulating ice, different superionic phases and liquid water inside ice giants.}, author = {Cheng, Bingqing and Bethkenhagen, Mandy and Pickard, Chris J. and Hamel, Sebastien}, issn = {1745-2481}, journal = {Nature Physics}, number = {11}, pages = {1228--1232}, publisher = {Springer Nature}, title = {{Phase behaviours of superionic water at planetary conditions}}, doi = {10.1038/s41567-021-01334-9}, volume = {17}, year = {2021}, } @article{10365, abstract = {The early development of many organisms involves the folding of cell monolayers, but this behaviour is difficult to reproduce in vitro; therefore, both mechanistic causes and effects of local curvature remain unclear. Here we study epithelial cell monolayers on corrugated hydrogels engineered into wavy patterns, examining how concave and convex curvatures affect cellular and nuclear shape. We find that substrate curvature affects monolayer thickness, which is larger in valleys than crests. We show that this feature generically arises in a vertex model, leading to the hypothesis that cells may sense curvature by modifying the thickness of the tissue. We find that local curvature also affects nuclear morphology and positioning, which we explain by extending the vertex model to take into account membrane–nucleus interactions, encoding thickness modulation in changes to nuclear deformation and position. We propose that curvature governs the spatial distribution of yes-associated proteins via nuclear shape and density changes. We show that curvature also induces significant variations in lamins, chromatin condensation and cell proliferation rate in folded epithelial tissues. Together, this work identifies active cell mechanics and nuclear mechanoadaptation as the key players of the mechanistic regulation of epithelia to substrate curvature.}, author = {Luciano, Marine and Xue, Shi-lei and De Vos, Winnok H. and Redondo-Morata, Lorena and Surin, Mathieu and Lafont, Frank and Hannezo, Edouard B and Gabriele, Sylvain}, issn = {1745-2481}, journal = {Nature Physics}, number = {12}, pages = {1382–1390}, publisher = {Springer Nature}, title = {{Cell monolayers sense curvature by exploiting active mechanics and nuclear mechanoadaptation}}, doi = {10.1038/s41567-021-01374-1}, volume = {17}, year = {2021}, } @article{10617, abstract = {When a flat band is partially filled with electrons, strong Coulomb interactions between them may lead to the emergence of topological gapped states with quantized Hall conductivity. Such emergent topological states have been found in partially filled Landau levels1 and Hofstadter bands2,3; however, in both cases, a large magnetic field is required to produce the underlying flat band. The recent observation of quantum anomalous Hall effects in narrow-band moiré materials4,5,6,7 has led to the theoretical prediction that such phases could be realized at zero magnetic field8,9,10,11,12. Here we report the observation of insulators with Chern number C = 1 in the zero-magnetic-field limit at half-integer filling of the moiré superlattice unit cell in twisted monolayer–bilayer graphene7,13,14,15. Chern insulators in a half-filled band suggest the spontaneous doubling of the superlattice unit cell2,3,16, and our calculations find a ground state of the topological charge density wave at half-filling of the underlying band. The discovery of these topological phases at fractional superlattice filling enables the further pursuit of zero-magnetic-field phases that have fractional statistics that exist either as elementary excitations or bound to lattice dislocations.}, author = {Polshyn, Hryhoriy and Zhang, Y. and Kumar, M. A. and Soejima, T. and Ledwith, P. and Watanabe, K. and Taniguchi, T. and Vishwanath, A. and Zaletel, M. P. and Young, A. F.}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {general physics, astronomy}, publisher = {Springer Nature}, title = {{Topological charge density waves at half-integer filling of a moiré superlattice}}, doi = {10.1038/s41567-021-01418-6}, year = {2021}, } @article{8673, abstract = {In RuCl3, inelastic neutron scattering and Raman spectroscopy reveal a continuum of non-spin-wave excitations that persists to high temperature, suggesting the presence of a spin liquid state on a honeycomb lattice. In the context of the Kitaev model, finite magnetic fields introduce interactions between the elementary excitations, and thus the effects of high magnetic fields that are comparable to the spin-exchange energy scale must be explored. Here, we report measurements of the magnetotropic coefficient—the thermodynamic coefficient associated with magnetic anisotropy—over a wide range of magnetic fields and temperatures. We find that magnetic field and temperature compete to determine the magnetic response in a way that is independent of the large intrinsic exchange-interaction energy. This emergent scale-invariant magnetic anisotropy provides evidence for a high degree of exchange frustration that favours the formation of a spin liquid state in RuCl3.}, author = {Modic, Kimberly A and McDonald, Ross D. and Ruff, J.P.C. and Bachmann, Maja D. and Lai, You and Palmstrom, Johanna C. and Graf, David and Chan, Mun K. and Balakirev, F.F. and Betts, J.B. and Boebinger, G.S. and Schmidt, Marcus and Lawler, Michael J. and Sokolov, D.A. and Moll, Philip J.W. and Ramshaw, B.J. and Shekhter, Arkady}, issn = {1745-2481}, journal = {Nature Physics}, pages = {240--244}, publisher = {Springer Nature}, title = {{Scale-invariant magnetic anisotropy in RuCl3 at high magnetic fields}}, doi = {10.1038/s41567-020-1028-0}, volume = {17}, year = {2021}, } @article{8602, abstract = {Collective cell migration offers a rich field of study for non-equilibrium physics and cellular biology, revealing phenomena such as glassy dynamics, pattern formation and active turbulence. However, how mechanical and chemical signalling are integrated at the cellular level to give rise to such collective behaviours remains unclear. We address this by focusing on the highly conserved phenomenon of spatiotemporal waves of density and extracellular signal-regulated kinase (ERK) activation, which appear both in vitro and in vivo during collective cell migration and wound healing. First, we propose a biophysical theory, backed by mechanical and optogenetic perturbation experiments, showing that patterns can be quantitatively explained by a mechanochemical coupling between active cellular tensions and the mechanosensitive ERK pathway. Next, we demonstrate how this biophysical mechanism can robustly induce long-ranged order and migration in a desired orientation, and we determine the theoretically optimal wavelength and period for inducing maximal migration towards free edges, which fits well with experimentally observed dynamics. We thereby provide a bridge between the biophysical origin of spatiotemporal instabilities and the design principles of robust and efficient long-ranged migration.}, author = {Boocock, Daniel R and Hino, Naoya and Ruzickova, Natalia and Hirashima, Tsuyoshi and Hannezo, Edouard B}, issn = {1745-2481}, journal = {Nature Physics}, pages = {267--274}, publisher = {Springer Nature}, title = {{Theory of mechanochemical patterning and optimal migration in cell monolayers}}, doi = {10.1038/s41567-020-01037-7}, volume = {17}, year = {2021}, } @article{9428, abstract = {Thermalization is the inevitable fate of many complex quantum systems, whose dynamics allow them to fully explore the vast configuration space regardless of the initial state---the behaviour known as quantum ergodicity. In a quest for experimental realizations of coherent long-time dynamics, efforts have focused on ergodicity-breaking mechanisms, such as integrability and localization. The recent discovery of persistent revivals in quantum simulators based on Rydberg atoms have pointed to the existence of a new type of behaviour where the system rapidly relaxes for most initial conditions, while certain initial states give rise to non-ergodic dynamics. This collective effect has been named ”quantum many-body scarring’by analogy with a related form of weak ergodicity breaking that occurs for a single particle inside a stadium billiard potential. In this Review, we provide a pedagogical introduction to quantum many-body scars and highlight the emerging connections with the semiclassical quantization of many-body systems. We discuss the relation between scars and more general routes towards weak violations of ergodicity due to embedded algebras and non-thermal eigenstates, and highlight possible applications of scars in quantum technology.}, author = {Serbyn, Maksym and Abanin, Dmitry A. and Papić, Zlatko}, issn = {1745-2481}, journal = {Nature Physics}, number = {6}, pages = {675–685}, publisher = {Nature Research}, title = {{Quantum many-body scars and weak breaking of ergodicity}}, doi = {10.1038/s41567-021-01230-2}, volume = {17}, year = {2021}, } @article{13999, abstract = {Attosecond chronoscopy has revealed small but measurable delays in photoionization, characterized by the ejection of an electron on absorption of a single photon. Ionization-delay measurements in atomic targets provide a wealth of information about the timing of the photoelectric effect, resonances, electron correlations and transport. However, extending this approach to molecules presents challenges, such as identifying the correct ionization channels and the effect of the anisotropic molecular landscape on the measured delays. Here, we measure ionization delays from ethyl iodide around a giant dipole resonance. By using the theoretical value for the iodine atom as a reference, we disentangle the contribution from the functional ethyl group, which is responsible for the characteristic chemical reactivity of a molecule. We find a substantial additional delay caused by the presence of a functional group, which encodes the effect of the molecular potential on the departing electron. Such information is inaccessible to the conventional approach of measuring photoionization cross-sections. The results establish ionization-delay measurements as a valuable tool in investigating the electronic properties of molecules.}, author = {Biswas, Shubhadeep and Förg, Benjamin and Ortmann, Lisa and Schötz, Johannes and Schweinberger, Wolfgang and Zimmermann, Tomáš and Pi, Liangwen and Baykusheva, Denitsa Rangelova and Masood, Hafiz A. and Liontos, Ioannis and Kamal, Amgad M. and Kling, Nora G. and Alharbi, Abdullah F. and Alharbi, Meshaal and Azzeer, Abdallah M. and Hartmann, Gregor and Wörner, Hans J. and Landsman, Alexandra S. and Kling, Matthias F.}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {General Physics and Astronomy}, number = {7}, pages = {778--783}, publisher = {Springer Nature}, title = {{Probing molecular environment through photoemission delays}}, doi = {10.1038/s41567-020-0887-8}, volume = {16}, year = {2020}, } @article{10701, abstract = {Partially filled Landau levels host competing electronic orders. For example, electron solids may prevail close to integer filling of the Landau levels before giving way to fractional quantum Hall liquids at higher carrier density1,2. Here, we report the observation of an electron solid with non-collinear spin texture in monolayer graphene, consistent with solidification of skyrmions3—topological spin textures characterized by quantized electrical charge4,5. We probe the spin texture of the solids using a modified Corbino geometry that allows ferromagnetic magnons to be launched and detected6,7. We find that magnon transport is highly efficient when one Landau level is filled (ν=1), consistent with quantum Hall ferromagnetic spin polarization. However, even minimal doping immediately quenches the magnon signal while leaving the vanishing low-temperature charge conductivity unchanged. Our results can be understood by the formation of a solid of charged skyrmions near ν=1, whose non-collinear spin texture leads to rapid magnon decay. Data near fractional fillings show evidence of several fractional skyrmion solids, suggesting that graphene hosts a highly tunable landscape of coupled spin and charge orders.}, author = {Zhou, Haoxin and Polshyn, Hryhoriy and Taniguchi, Takashi and Watanabe, Kenji and Young, Andrea F.}, issn = {1745-2481}, journal = {Nature Physics}, number = {2}, pages = {154--158}, publisher = {Springer Nature}, title = {{Skyrmion solids in monolayer graphene}}, doi = {10.1038/s41567-019-0729-8}, volume = {16}, year = {2020}, } @article{7942, abstract = {An understanding of the missing antinodal electronic excitations in the pseudogap state is essential for uncovering the physics of the underdoped cuprate high-temperature superconductors1,2,3,4,5,6. The majority of high-temperature experiments performed thus far, however, have been unable to discern whether the antinodal states are rendered unobservable due to their damping or whether they vanish due to their gapping7,8,9,10,11,12,13,14,15,16,17,18. Here, we distinguish between these two scenarios by using quantum oscillations to examine whether the small Fermi surface pocket, found to occupy only 2% of the Brillouin zone in the underdoped cuprates19,20,21,22,23,24, exists in isolation against a majority of completely gapped density of states spanning the antinodes, or whether it is thermodynamically coupled to a background of ungapped antinodal states. We find that quantum oscillations associated with the small Fermi surface pocket exhibit a signature sawtooth waveform characteristic of an isolated two-dimensional Fermi surface pocket25,26,27,28,29,30,31,32. This finding reveals that the antinodal states are destroyed by a hard gap that extends over the majority of the Brillouin zone, placing strong constraints on a drastic underlying origin of quasiparticle disappearance over almost the entire Brillouin zone in the pseudogap regime7,8,9,10,11,12,13,14,15,16,17,18.}, author = {Hartstein, Máté and Hsu, Yu Te and Modic, Kimberly A and Porras, Juan and Loew, Toshinao and Tacon, Matthieu Le and Zuo, Huakun and Wang, Jinhua and Zhu, Zengwei and Chan, Mun K. and Mcdonald, Ross D. and Lonzarich, Gilbert G. and Keimer, Bernhard and Sebastian, Suchitra E. and Harrison, Neil}, issn = {1745-2481}, journal = {Nature Physics}, pages = {841--847}, publisher = {Springer Nature}, title = {{Hard antinodal gap revealed by quantum oscillations in the pseudogap regime of underdoped high-Tc superconductors}}, doi = {10.1038/s41567-020-0910-0}, volume = {16}, year = {2020}, } @article{6976, abstract = {Origami is rapidly transforming the design of robots1,2, deployable structures3,4,5,6 and metamaterials7,8,9,10,11,12,13,14. However, as foldability requires a large number of complex compatibility conditions that are difficult to satisfy, the design of crease patterns is limited to heuristics and computer optimization. Here we introduce a systematic strategy that enables intuitive and effective design of complex crease patterns that are guaranteed to fold. First, we exploit symmetries to construct 140 distinct foldable motifs, and represent these as jigsaw puzzle pieces. We then show that when these pieces are fitted together they encode foldable crease patterns. This maps origami design to solving combinatorial problems, which allows us to systematically create, count and classify a vast number of crease patterns. We show that all of these crease patterns are pluripotent—capable of folding into multiple shapes—and solve exactly for the number of possible shapes for each pattern. Finally, we employ our framework to rationally design a crease pattern that folds into two independently defined target shapes, and fabricate such pluripotent origami. Our results provide physicists, mathematicians and engineers with a powerful new design strategy.}, author = {Dieleman, Peter and Vasmel, Niek and Waitukaitis, Scott R and van Hecke, Martin}, issn = {1745-2481}, journal = {Nature Physics}, number = {1}, pages = {63–68}, publisher = {Springer Nature}, title = {{Jigsaw puzzle design of pluripotent origami}}, doi = {10.1038/s41567-019-0677-3}, volume = {16}, year = {2020}, } @article{10620, abstract = {Partially filled Landau levels host competing electronic orders. For example, electron solids may prevail close to integer filling of the Landau levels before giving way to fractional quantum Hall liquids at higher carrier density1,2. Here, we report the observation of an electron solid with non-collinear spin texture in monolayer graphene, consistent with solidification of skyrmions3—topological spin textures characterized by quantized electrical charge4,5. We probe the spin texture of the solids using a modified Corbino geometry that allows ferromagnetic magnons to be launched and detected6,7. We find that magnon transport is highly efficient when one Landau level is filled (ν=1), consistent with quantum Hall ferromagnetic spin polarization. However, even minimal doping immediately quenches the magnon signal while leaving the vanishing low-temperature charge conductivity unchanged. Our results can be understood by the formation of a solid of charged skyrmions near ν=1, whose non-collinear spin texture leads to rapid magnon decay. Data near fractional fillings show evidence of several fractional skyrmion solids, suggesting that graphene hosts a highly tunable landscape of coupled spin and charge orders.}, author = {Zhou, H. and Polshyn, Hryhoriy and Taniguchi, T. and Watanabe, K. and Young, A. F.}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {General Physics and Astronomy}, number = {2}, pages = {154--158}, publisher = {Springer Nature}, title = {{Solids of quantum Hall skyrmions in graphene}}, doi = {10.1038/s41567-019-0729-8}, volume = {16}, year = {2019}, } @article{10621, abstract = {Twisted bilayer graphene has recently emerged as a platform for hosting correlated phenomena. For twist angles near θ ≈ 1.1°, the low-energy electronic structure of twisted bilayer graphene features isolated bands with a flat dispersion1,2. Recent experiments have observed a variety of low-temperature phases that appear to be driven by electron interactions, including insulating states, superconductivity and magnetism3,4,5,6. Here we report electrical transport measurements up to room temperature for twist angles varying between 0.75° and 2°. We find that the resistivity, ρ, scales linearly with temperature, T, over a wide range of T before falling again owing to interband activation. The T-linear response is much larger than observed in monolayer graphene for all measured devices, and in particular increases by more than three orders of magnitude in the range where the flat band exists. Our results point to the dominant role of electron–phonon scattering in twisted bilayer graphene, with possible implications for the origin of the observed superconductivity.}, author = {Polshyn, Hryhoriy and Yankowitz, Matthew and Chen, Shaowen and Zhang, Yuxuan and Watanabe, K. and Taniguchi, T. and Dean, Cory R. and Young, Andrea F.}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {general physics and astronomy}, number = {10}, pages = {1011--1016}, publisher = {Springer Nature}, title = {{Large linear-in-temperature resistivity in twisted bilayer graphene}}, doi = {10.1038/s41567-019-0596-3}, volume = {15}, year = {2019}, } @article{21545, abstract = {Free-electron radiation such as Cerenkov1, Smith–Purcell2 and transition radiation3,4 can be greatly affected by structured optical environments, as has been demonstrated in a variety of polaritonic5,6, photonic-crystal7 and metamaterial8,9,10 systems. However, the amount of radiation that can ultimately be extracted from free electrons near an arbitrary material structure has remained elusive. Here we derive a fundamental upper limit to the spontaneous photon emission and energy loss of free electrons, regardless of geometry, which illuminates the effects of material properties and electron velocities. We obtain experimental evidence for our theory with quantitative measurements of Smith–Purcell radiation. Our framework allows us to make two predictions. One is a new regime of radiation operation—at subwavelength separations, slower (non-relativistic) electrons can achieve stronger radiation than fast (relativistic) electrons. The other is a divergence of the emission probability in the limit of lossless materials. We further reveal that such divergences can be approached by coupling free electrons to photonic bound states in the continuum11,12,13. Our findings suggest that compact and efficient free-electron radiation sources from microwaves to the soft X-ray regime may be achievable without requiring ultrahigh accelerating voltages.}, author = {Yang, Yi and Massuda, Aviram and Roques-Carmes, Charles and Kooi, Steven E. and Christensen, Thomas and Johnson, Steven G. and Joannopoulos, John D. and Miller, Owen D. and Kaminer, Ido and Soljačić, Marin}, issn = {1745-2481}, journal = {Nature Physics}, pages = {894--899}, publisher = {Springer Nature}, title = {{Maximal spontaneous photon emission and energy loss from free electrons}}, doi = {10.1038/s41567-018-0180-2}, volume = {14}, year = {2018}, } @article{9062, abstract = {Self-assembly is the autonomous organization of components into patterns or structures: an essential ingredient of biology and a desired route to complex organization1. At equilibrium, the structure is encoded through specific interactions2,3,4,5,6,7,8, at an unfavourable entropic cost for the system. An alternative approach, widely used by nature, uses energy input to bypass the entropy bottleneck and develop features otherwise impossible at equilibrium9. Dissipative building blocks that inject energy locally were made available by recent advances in colloidal science10,11 but have not been used to control self-assembly. Here we show the targeted formation of self-powered microgears from active particles and their autonomous synchronization into dynamical superstructures. We use a photoactive component that consumes fuel, haematite, to devise phototactic microswimmers that form self-spinning microgears following spatiotemporal light patterns. The gears are coupled via their chemical clouds by diffusiophoresis12 and constitute the elementary bricks of synchronized superstructures, which autonomously regulate their dynamics. The results are quantitatively rationalized on the basis of a stochastic description of diffusio-phoretic oscillators dynamically coupled by chemical gradients. Our findings harness non-equilibrium phoretic phenomena to program interactions and direct self-assembly with fidelity and specificity. It lays the groundwork for the autonomous construction of dynamical architectures and functional micro-machinery.}, author = {Aubret, Antoine and Youssef, Mena and Sacanna, Stefano and Palacci, Jérémie A}, issn = {1745-2481}, journal = {Nature Physics}, number = {11}, pages = {1114--1118}, publisher = {Springer Nature}, title = {{Targeted assembly and synchronization of self-spinning microgears}}, doi = {10.1038/s41567-018-0227-4}, volume = {14}, year = {2018}, } @article{10378, abstract = {The ability of biological molecules to replicate themselves is the foundation of life, requiring a complex cellular machinery. However, a range of aberrant processes involve the self-replication of pathological protein structures without any additional assistance. One example is the autocatalytic generation of pathological protein aggregates, including amyloid fibrils, involved in neurodegenerative disorders. Here, we use computer simulations to identify the necessary requirements for the self-replication of fibrillar assemblies of proteins. We establish that a key physical determinant for this process is the affinity of proteins for the surfaces of fibrils. We find that self-replication can take place only in a very narrow regime of inter-protein interactions, implying a high level of sensitivity to system parameters and experimental conditions. We then compare our theoretical predictions with kinetic and biosensor measurements of fibrils formed from the Aβ peptide associated with Alzheimer’s disease. Our results show a quantitative connection between the kinetics of self-replication and the surface coverage of fibrils by monomeric proteins. These findings reveal the fundamental physical requirements for the formation of supra-molecular structures able to replicate themselves, and shed light on mechanisms in play in the proliferation of protein aggregates in nature.}, author = {Šarić, Anđela and Buell, Alexander K. and Meisl, Georg and Michaels, Thomas C. T. and Dobson, Christopher M. and Linse, Sara and Knowles, Tuomas P. J. and Frenkel, Daan}, issn = {1745-2481}, journal = {Nature Physics}, keywords = {general physics and astronomy}, number = {9}, pages = {874--880}, publisher = {Springer Nature}, title = {{Physical determinants of the self-replication of protein fibrils}}, doi = {10.1038/nphys3828}, volume = {12}, year = {2016}, }