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: Biao Huang | Summary:In process operations, it is desirable to manage the sensitivity of the system output against external disturbance in the form of finite $mathcalL_2$-gain stabilization. This matter is, however, nonsensical for stochastic systems because the stochastic uncertainties in the control input almost always lead to an unbounded $mathcalL_2$ gain from the […]
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: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: Mamoru Matsuo | Summary:We extend ferromagnetic resonance (FMR) modulation theory to describe systems in which bulk and boundary states of topological materials coexist, with both appearing at the same energy. As an application of the formulation, we investigate the enhancement of the Gilbert damping constant on the $(110)$ surface of a $d$-wave superconductor […]
Kavli Affiliate: Rudolf Podgornik | Summary:We study the effect of asymmetry in solvent and ionic size on the equilibrium properties of multivalent ionic solutions near a charged surface. For a single ionic species in solution, we derive a generalized Grahame equation at the charged surface. For general size ratio between the ions and the solvent, […]
Kavli Affiliate: Mamoru Matsuo | Summary:We theoretically investigate the current-induced excitation of torsional vibrations in a suspended carbon nanotube (CNT) quantum dot. By considering a CNT clamped between half-metallic ferromagnetic electrodes with an antiparallel magnetization configuration, we demonstrate that the spin-rotation coupling enables the transfer of angular momentum from electron spins to the mechanical torsional […]
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: Mamoru Matsuo | Summary:We theoretically investigate spin-valley-locked tunneling transport in a transition-metal dichalcogenide/ferromagnetic-insulator heterostructure under a perpendicular magnetic field, driven by the spin Seebeck effect. We demonstrate that spin-valley coupling together with the magnetic-field-induced valley-asymmetric Landau-level structure enables the generation of a valley-polarized spin current from valley-selective spin excitation. We compare the spin […]