Related papers: Nesting Induced Peierls-type Instability for Compr…
Recently reported structural complexity and superconducting transition in lithium under pressure has increased the interest in light alkalis, otherwise considered as simple metals and well known systems under normal conditions. In this work…
The concept of a CDW induced by Fermi-surface nesting originated from the Peierls idea of electronic instabilities in purely 1D metals and is now often applied to charge ordering in real low-dimensional materials. The idea is that if Fermi…
The Fermi surface topology of $cI$16 Li at high pressures is studied using a recently developed first-principles unfolding method. We find the occurrence of a Lifshitz transition at $\sim$43 GPa, which explains the experimentally observed…
Lithium - the lightest alkali metal - exhibits unexpected structures and electronic behaviour at high pressures. As the heavier alkalis, Li is bcc at ambient pressure and transforms first to fcc (at 7.5 GPa). The post-fcc high-pressure form…
Light alkali metals have usually been considered as simple metals due to their monovalency and high conductivity. In these metals ionic pseudopotentials are weak and the nearly free electron model (NFE) becomes quite accurate at normal…
The formation of a charge density wave (CDW) in two-dimensional (2D) materials caused by Peierls instability is a controversial topic. This study investigates the extensively debated role of Fermi surface nesting in causing the CDW state in…
Based on a half-filled two-dimensional tight-binding model with nearest-neighbour and next nearest-neighbour hopping the effect of imperfect Fermi surface nesting on the Peierls instability is studied at zero temperature. Two dimerization…
Detailed structural and magnetotransport properties of the monophosphate tungsten bronze K$_{x}$P$_4$W$_{8}$O$_{32}$ single crystals are reported. Both galvanomagnetic and thermal properties are shown to be consistent with a charge density…
We argue that an ionic lattice surrounded by a Fermi liquid changes phase several times under pressure, oscillating between the symmetric phase and a low-symmetry dimerized structure, as a consequence of Friedel oscillations in the pair…
The understanding of lattice instabilities is of vast importance in material science. The famous example is the Peierls instability of one-dimensional metals and for strongly-nested Fermi surfaces in two and three dimensions. Through an…
The metal-semiconductor-metal transition in dense lithium is considered as an archetype of interplay between interstitial electron localization and delocalization induced by compression, which leads to exotic electride phases. In this work,…
Since their theoretical prediction by Peierls in the 30s, charge density waves (CDW) have been one of the most commonly encountered electronic phases in low dimensional metallic systems. The instability mechanism originally proposed…
The rare earth nickel borocarbides, with the generic formula $R$Ni$_{2}$B$_{2}$C, have recently been shown to display a rich variety of phenomena. Most striking has been the competition between, and even coexistence of, antiferromagnetism…
Lithium, a prototypical simple metal under ambient conditions, has a surprisingly rich phase diagram under pressure, taking up several structures with reduced symmetry, low coordination numbers, and even semiconducting character with…
The electronic structure of pure niobium and the niobium-titanium alloy Nb$_{0.44}$Ti$_{0.56}$ in the bcc-phase at pressures up to $250$ GPa is investigated, to reveal possible factors conducing toward the robust superconductivity reported…
Interplay of Fermi surface topology and electron correlation is the quintessential ingredient underlying spontaneous symmetry breaking in itinerant electronic systems. In one-dimensional (1D) systems at half-filling, the inherent Fermi…
We used high resolution angle-resolved photoemission spectroscopy to reveal the Fermi surface and key transport parameters of the metallic state of the layered Colossal Magnetoresistive (CMR) oxide La1.2Sr1.8Mn2O7. With these parameters the…
The effect of strong anisotropy on the Fermi line of a system of correlated electrons is studied in two space dimensions, using renormalization group techniques. Inflection points change the scaling exponents of the couplings, enhancing the…
Using Migdal-Eliashberg theory implemented in Electron Phonon Wannier (EPW) code, we have investigated anisotropic superconductivity in a ternary boride $\mathrm{Ta(MoB)_2}$. It is a single-gap, anisotropic, phonon-mediated superconductor…
Recent high-pressure x-ray diffraction studies of alkali metals revealed unusual complex structures that follow the body-centered and face-centered cubic structures on compression. The structural sequence of potassium under compression to 1…