Related papers: Ice: a strongly correlated proton system
The D2O ice VI to ice XV hydrogen ordering phase transition at ambient pressure is investigated in detail with neutron diffraction. The lattice constants are found to be sensitive indicators for hydrogen ordering. The a and b lattice…
It has been known since the pioneering work of Bernal, Fowler and Pauling that common, hexagonal (Ih) water ice is the archetype of a frustrated material : a proton-bonded network in which protons satisfy strong local constraints - the "ice…
Using numerical simulations that mimic recent experiments on hexagonal colloidal ice, we show that colloidal hexagonal artificial spin ice exhibits an inner phase within its ice state that has not been observed previously. Under increasing…
We use electron momentum density in ice as a tool to quantify order-disorder transitions by comparing Compton profiles differences of ice VI, VII, VIII and XII with respect to ice Ih. Quantitative agreement is found between theory and…
In part I of this paper the electric behaviour of pure water is described by an interstitial-ice model, the so-called Protonic-Semiconductor Interstitial-Ice or PSII model. Liquid water consists of an intact ice-like lattice with a…
Most experimentally known high-pressure ice phases have a body-centred cubic (bcc) oxygen lattice. Our atomistic simulations show that, amongst these bcc ice phases, ices VII, VII' and X are the same thermodynamic phase under different…
Ever since the first observation of Bose-Einstein condensation in the nineties, ultracold quantum gases have been the subject of intense research, providing a unique tool to understand the behavior of matter governed by the laws of quantum…
We investigate the ground-state phase diagram of the one-dimensional "ionic" Hubbard model with an alternating periodic potential at half-filling by numerical diagonalization of finite systems with the Lanczos and density matrix…
Hydrogen hydrates (HH) are a unique class of materials composed of hydrogen molecules confined within crystalline water frameworks. Among their multiple phases, the filled ice structures, particularly the cubic C2 phase, exhibit…
The phase diagram of water harbours many mysteries: some of the phase boundaries are fuzzy, and the set of known stable phases may not be complete. Starting from liquid water and a comprehensive set of 50 ice structures, we compute the…
The 3d electronic structure and phase transition in pure and Cr doped V2O3 are theoretically investigated in relation to the 3d spin-orbit interaction and lattice distortion. A model consisting of the nearest-neighbor V ion pair with full…
In the ionic Hubbard model, the onsite repulsion $U$, which drives a Mott insulator and the ionic potential $V$, which drives a band insulator, compete with each other to open up a window of charge fluctuations when $U \sim V$. We study…
Proton ordering in water ice is a paradigmatic order-disorder transition in a locally constrained system. The ice rules require exactly two hydrogens close to each oxygen, restricting the disorder to an exponentially large yet strongly…
Spin crossover materials contain metal ions that can access two spin-states: one low-spin (LS), the other high-spin (HS). We propose that frustrated elastic interactions can give rise to spin-state ices -- phases of matter without…
We study the phase diagram of a strongly coupled confining theory in $2+1$ dimensions, as a function of temperature and baryon chemical potential. The theory has a fully fledged supergravity holographic dual, that we use to predict a line…
We establish the phase diagram of the disordered three-dimensional Bose-Hubbard model at unity filling, which has been controversial for many years. The theorem of inclusions, proven in Ref. [1], states that the Bose glass phase always…
Currently ~36 different absorption bands have been detected in the infrared spectra of cold, dense interstellar and circumstellar environments. These are attributed to the vibrational transitions of ~17 different molecules frozen on dust…
The mobility of atoms, molecules and radicals in icy grain mantles regulate ice restructuring, desorption, and chemistry in astrophysical environments. Interstellar ices are dominated by H2O, and diffusion on external and internal (pore)…
Several experimental and theoretical studies report instances of concerted or correlated multiple proton tunneling in solid phases of water. Here, we construct a pseudo-spin model for the quantum motion of protons in a hexameric H$_2$O ring…
A frustrated system is one whose symmetry precludes the possibility that every pairwise interaction (``bond'') in the system can be satisfied at the same time. Such systems are common in all areas of physical and biological science. In the…