Abstract We employ electronic structure calculations to show that a (111)-oriented (LaMnO 3 ) 12 ∣(SrMnO 6 superlattice retains half-metallic ferromagnetic character despite its large thickness. link this behaviour the strain and octahedral connectivity between layers. This also gives rise breathing modes, which are coupled charge spin oscillations, whose components have pure e g character. Mos...

Divalent Eu (4f;{7}, J=7/2) possesses a strong local magnetic moment which suppresses superconductivity. Under sufficient pressure it is anticipated that Eu will become trivalent (4f;{6}, J=0) and a weak Van Vleck paramagnet, thus opening the door for a possible superconducting state, in analogy with Am metal (5f;{6}, J=0) which superconducts at 0.79 K. We present ac susceptibility and electric...

Of the 52 known elemental superconductors among the 92 naturally occurring elements in the periodic table, fully 22 only become superconducting under sufficiently high pressure. In the rare-earth metals, the strong local magnetic moments originating from the 4f shell suppress superconductivity. For Eu, however, Johansson and Rosengren have suggested that sufficiently high pressures should promo...

The calculation of linear and nonlinear optical response as well as nonadiabatic curve crossing processes depends on the time evolution of the electronic coherences ~off-diagonal elements of the density matrix!. Unlike their diagonal counterparts, the off-diagonal elements do not have an obvious classical limit. A semiclassical approximation for the nonlinear optical response function, which re...

We show that quantum entanglement, nowadays so widely observed and used in a multitude of systems, can be traced in the atomic spins of metal clusters supported on metal surfaces. Most importantly, we show that it can be voluntarily altered with external electric fields. We use a combination of ab initio and model Heisenberg-Dirac-Van Vleck quantum spin Hamiltonian calculations to show, with th...

Determination of the water vapor continuum absorption from 0.35 to 1 THz is reported. The THz pulses propagate though a 137 m long humidity-controlled chamber and are measured by THz time-domain spectroscopy (THz-TDS). The average relative humidity along the entire THz path is precisely obtained by measuring the difference between transit times of the sample and reference THz pulses to an accur...

The presence of spin-orbit (SO) interaction in a noncentrosymmetric superconductor, La2C3 (Tc ≃ 11 K) is demonstrated by muon spin rotation (μSR) in its normal state, where μSR spectra exhibit field-induced weak depolarization due to van Vleck-like local susceptibility. In the mixed state, muon spin relaxation due to inhomogeneity of internal field (σv) exhibits a field dependence that is chara...

We present accurately calibrated submillimeter atmospheric transmission spectra obtained with a Fourier-transform spectrometer at the Caltech Submillimeter Observatory on Mauna Kea, Hawaii. These measurements cover the 0.9-0.3-mm wavelength range and are the first in a series aimed at defining the terrestrial long-wave atmospheric transmission curve. The 4.1-km altitude of the Mauna Kea site pr...

We consider the dissipative dynamics of a qubit coupled to a nonlinear oscillator (NO) embedded in an Ohmic environment. By treating the nonlinearity up to first order and applying Van Vleck perturbation theory up to second order in the qubit-NO coupling, we derive an analytical expression for the eigenstates and eigenfunctions of the coupled qubit-NO system beyond the rotating wave approximati...