Kavli Affiliate: Leon Balents | Summary:We study an effective low-energy Kondo model on the triangular lattice in which itinerant electrons occupy a valence pocket at $Γ$ and three conduction pockets at the $M$ points of the Brillouin zone. This construction has a Fermi-surface nesting structure that favors triple-$Q$ magnetic order while only assuming the low-energy […]
Kavli Affiliate: Matthew Fisher | Summary:Symmetry-based classification of quantum phases of matter is one of the most foundational organizing principles in physics; however, an analogous framework for mixed, decohered quantum states has only begun to emerge. A central new concept is strong-to-weak spontaneous symmetry breaking (SW-SSB), a sharp transition in mixed quantum states that is […]
Kavli Affiliate: Leon Balents | Summary:We present a systematic classification and variational study of chiral quantum spin liquids on the pyrochlore lattice based on fermionic parton constructions. Focusing on chiral $mathrmU(1)$ and $mathbbZ_2$ spin-liquid Ansätze, we characterize their symmetry properties, flux structures, and low-energy spinon spectra within a projective symmetry group framework, and incorporate gauge […]
Kavli Affiliate: Leon Balents | Summary:In this work, we perform ultrafast time-resolved reflectivity measurements to track the evolution of charge density wave (CDW) correlations in Sn-doped Kagome superconductor CsV$_3$Sb$_5-x$Sn$_x$. By extracting the coherent phonon spectrum, we evidence robust signatures of CDW correlations at temperature and doping ranges far beyond the phase boundary of long-range CDW […]
Kavli Affiliate: Matthew Fisher | Summary:We explore the onset of spontaneous strong-to-weak symmetry breaking (SW-SSB) under U(1)-symmetric (i.e., charge-conserving) open-system dynamics. We define this phenomenon for quantum states and classical probability distributions, and explore it in three complementary models, one of which exhibits nontrivial quantum coherence at short times. Our main conclusions are as follows. […]
Kavli Affiliate: Boris I. Shraiman | Summary:Connecting cell behavior to tissue shape and mechanics is a fundamental challenge in the physics of morphogenesis. In epithelia, cell-cell interfaces are under internal active tension, and cytoskeletal turnover precludes a fixed "reference shape" that could anchor conventional elastic theory. This "tension-first" setting calls for a different approach. Here, […]
Kavli Affiliate: Boris I. Shraiman | Summary:In contrast to inert materials, living cells use molecular motors to generate forces independently of elastic strain. How do local active forces translate into large-scale shape, and what are the mechanical properties of the resulting "living matter"? Here, we address these questions within the active tension network (ATN) model […]
Kavli Affiliate: Leon Balents | Summary:We study Gutzwiller-projected wavefunctions for triangular-lattice U(1) Dirac spin liquids in a Zeeman field, where we allow the U(1) gauge field to develop a gauge flux, resulting in (spin-split) spinon Landau levels. We find that at a given magnetization, the optimal candidate state has a finite flux chosen such that […]
Kavli Affiliate: Boris I. Shraiman | Summary:A constitutive relation between stress and strain relative to a reference state is the basic assumption of elasticity theory. However, in living matter, force generation is governed by motor molecule activity, which does not depend on deformation relative to a reference. A different approach is needed to describe how […]
Kavli Affiliate: Boris I. Shraiman | Summary:A constitutive relation between stress and strain relative to a reference state is the basic assumption of elasticity theory. However, in living matter, stress is governed by (motor molecule) activity rather than a constitutive law. What paradigm takes the place of elasticity in this setting? Here, we derive a […]