相关论文: Polarization Symmetry Breaking in Nitrogen under H…
Understanding high-pressure transitions in prototypical linear diatomic molecules, such as hydrogen, nitrogen, and oxygen, is an important objective in high-pressure physics. Recent ultrahigh-pressure study on hydrogen revealed that there…
Nitrogen represents an archetypal example of material exhibiting a pressure driven transformation from molecular to polymeric state. Detailed investigations of such transformations are challenging because of a large kinetic barrier between…
Diatomic nitrogen is an archetypal molecular system known for its exceptional stability and complex behavior at high pressures and temperatures, including rich solid polymorphism, formation of energetic states, and an insulator-to-metal…
We have mapped the molecular-atomic transition in liquid hydrogen using first principles molecular dynamics. We predict that a molecular phase with short-range orientational order exists at pressures above 100 GPa. The presence of this…
We report here a study of reversible pressure-induced structural transformation between two amorphous forms of SO$_2$: molecular at pressures below 26 GPa and polymeric above this pressure, at temperatures of 77 - 300 K. The transformation…
Carbon monoxide and nitrogen are among the potentially interesting high-energy density materials. However, in spite of the physical similarities of the molecules, they behave very differently at high pressures. Using density functional…
At high pressure, the typical behavior of elements dictated by the periodic table - including oxidation numbers, stoichiometries in compounds, and reactivity, to name but a few - is altered dramatically. As pressure is applied, the…
Nitrogen oxides are textbook class of molecular compounds, with extensive industrial applications. Nitrogen and oxygen are also among the most abundant elements in the universe. We explore the N-O system at 0 K and up to 500 GPa though ab…
A possible solution of the well known paradox of chiral molecules is based on the idea of spontaneous symmetry breaking. At low pressure the molecules are delocalized between the two minima of a given molecular potential while at higher…
Phase transitions and symmetry are intimately linked. Melting of ice, for example, restores translation invariance. The mysterious hidden order (HO) phase of URu$_2$Si$_2$ has, despite relentless research efforts, kept its symmetry breaking…
Recently [Phys. Rev. Lett. {\bf 106}, 093902 (2011)] it has been shown that $\mathcal{PT}$-symmetric scattering systems with balanced gain and loss, undergo a transition from $\mathcal{PT}$-symmetric scattering eigenstates, which are norm…
Sodium layered oxides often undergo phase transformations involving ordering or disordering of Na+ upon desodiation, i.e., when cycled as a battery electrode. Accurately characterizing these phases is crucial for understanding functional…
Understanding the behavior of molecular systems under pressure is a fundamental problem in condensed matter physics. In the case of nitrogen, the determination of the phase diagram and in particular of the melting line, are largely open…
In this letter we demonstrate universal symmetry breaking by means of magnetically induced circular dichroism. Magnetic field induces forbidden at zero field atomic transitions between $\Delta F = \pm2$ hyperfine levels. In a particular…
Polarization phenomena are essential for the understanding of elementary processes, and are typically large in the threshold region. The selection rules with respect to P-parity, angular momentum, isotopic spin and the Pauli principle allow…
We perform molecular dynamics simulations driven by accurate Quantum Monte Carlo forces on dense liquid hydrogen. Recently it has been reported a complete atomization transition between a mixed-atomic liquid and a completely dissociated…
We report an extraordinary pressure dependence of the magnetic interactions in the metal-organic system [(CuF$_2$(H$_2$O)$_2$)$_2$pyrazine]. At zero pressure, this material realizes a quasi-two-dimensional (Q2D) spin-1/2 square-lattice…
The phase diagram and stability limits of diatomic solid nitrogen have been explored in a wide pressure--temperature range by several optical spectroscopic techniques. A newly characterized narrow-gap semiconducting phase $\eta$ has been…
First-order phase transitions are characterized by a discontinuous first derivative of the Gibbs free energy, so that volumes and entropies are discontinuous. Such transitions are common in the crystalline state, but extremely rare in…
We study phase transition behavior of the Heisenberg model on a distorted triangular lattice with competing interactions. The ground-state phase diagram indicates that underlying symmetry can be changed by tuning parameters. We focus on two…