Hierarchy in the Static Fluctuation-Dissipation Theorem of One-Component Plasmas

Fluctuation-dissipation theorems (FDTs) link transport coefficients (density response functions, conductivities, electric susceptibilities, etc.) to equilibrium n-point correlation functions. Of special importance to us is the applications of the FDT to one component plasmas and binary ionic mixtures. When applied to such systems, the fluctuation-dissipation theorem provides invaluable insight into response functions and transport coefficients across the non-equilibrium spectrum. After an in-depth review of the FDT and linear response theory, we focus upon expanding the work of K.I. Golden and G. Kalman (J. Stat. Phys. 3, 87 (1972); Annals of Phys. 141, 160 (1982)) , which proposes a nonlinear response theory for magnetic field-free classical plasmas. We attempt to re-formulate the hierarchy of static fluctuation-dissipation relations in terms of external density response functions. This provides a systematic formalism for calculating higher order correlation functions in terms of lower-order ones. In future studies, we plan to derive relationships between the screened and external response functions in the RPA (or any suitable approximation method which takes account of particle correlation effects beyond the RPA). This will then provide insight into the hierarchy of static structure functions and their correlation functions

Signatures of a Majorana-Fermi surface in the Kitaev magnet Ag3_3LiIr2_2O6_6

Detecting Majorana fermions in experimental realizations of the Kitaev honeycomb model is often complicated by non-trivial interactions inherent to potential spin liquid candidates. In this work, we identify several distinct thermodynamic signatures of massive, itinerant Majorana fermions within the well-established analytical paradigm of Landau-Fermi liquid theory. We find a qualitative and quantitative agreement between the salient features of our Landau-Majorana liquid theory and the Kitaev spin liquid candidate Ag$_3$LiIr$_2$O$_6$. Our study presents strong evidence for a Fermi liquid-like ground state in the fundamental excitations of a honeycomb iridate, and opens new experimental avenues to detect itinerant Majorana fermions in condensed matter systems.Comment: 40 pages, 7 figure

Quantum Computing 2022

Quantum technology is full of figurative and literal noise obscuring its promise. In this overview, we will attempt to provide a sober assessment of the promise of quantum technology with a focus on computing. We provide a tour of quantum computing and quantum technology that is aimed to be comprehensible to scientists and engineers without becoming a popular account. The goal is not a comprehensive review nor a superficial introduction but rather to serve as a useful map to navigate the hype, the scientific literature, and upcoming press releases about quantum technology and quantum computing. We have aimed to cite the most recent topical reviews, key results, and guide the reader away from fallacies and towards active discussions in the current quantum computing literature. The goal of this article was to be pedantic and introductory without compromising on the science.Comment: 14 pages. Comments are welcome. Updated with additional quantum primacy result