Bcc 4^4He as a Coherent Quantum Solid

In this work we investigate implications of the quantum nature of bcc $^{4}$% He. We show that it is a unique solid phase with both a lattice structure and an Off-Diagonal Long Range Order of coherently oscillating local electric dipole moments. These dipoles arise from the local motion of the atoms in the crystal potential well, and oscillate in synchrony to reduce the dipolar interaction energy. The dipolar ground-state is therefore found to be a coherent state with a well defined global phase and a three-component complex order parameter. The condensation energy of the dipoles in the bcc phase stabilizes it over the hcp phase at finite temperatures. We further show that there can be fermionic excitations of this ground-state and predict that they form an optical-like branch in the (110) direction. A comparison with 'super-solid' models is also discussed.Comment: 12 pages, 8 figure

Variational Monte Carlo study of the ground state properties and vacancy formation energy of solid para-H2 using a shadow wave function

A Shadow Wave Function (SWF) is employed along with Variational Monte Carlo techniques to describe the ground state properties of solid molecular para-hydrogen. The study has been extended to densities below the equilibrium value, to obtain a parameterization of the SWF useful for the description of inhomogeneous phases. We also present an estimate of the vacancy formation energy as a function of the density, and discuss the importance of relaxation effects near the vacant site

Observation of a new excitation in bcc solid 4He by inelastic neutron scattering

We report neutron scattering measurements of the phonons in bcc solid 4He. In general, only 3 accoustic phonon branches should exist in a monoatomic cubic crystal. In addition to these phonon branches, we found a new ''optic-like'' mode along the [110] direction. One possible interpretation of this new mode is in terms of localized excitations unique to a quantum solid.Comment: Text and 4 figures, to appear in Phys. Rev. Let

QUANTUM THEOREM OF CORRESPONDING STATES AND SPIN-POLARIZED QUANTUM SYSTEM

On donne une revue des propriétés thermodynamiques des systèmes quantiques macroscopiques du point de vue du Théorème Quantique des Etats Correspondants. Ces résultats sont utilisés pour prédire et discuter les propriétés thermodynamiques des systèmes quantiques spin-polarisés.A review of the thermodynamic properties of macroscopic quantum systems is given from the unified point of view provided by the Quantum Theorem of Corresponding States. These results are used to predict and discuss the thermodynamic properties of spin-polarized quantum systems

Metastable states in strongly coupled quantum systems with continuous spectra

The problem of constructing metastable states in strongly coupled quantum systems whose spectra are continuous is treated within the context of the general perturbation method developed by Van Hove. The state is constructed in terms of the unperturbed states and its metastable character is proved without explicitly introducing the perturbed stationary states. An interesting feature of the result is that the construction of the state requires the use of a complex number, the real part of which is equal to the energy of the state while its imaginary part is juch larger than the line width of the state. The general result is applied to the Fermi gas and the Lee model. In the latter case it reduces to the result previously obtained by Glaser and Källén

To Bloom in Empty Space : An Introduction and Commentary on the Petichta to Esther Rabbah

The petichta to Esther Rabbah (c. 6th century CE) reflects a pessimistic rabbinic response to the physical and theological displacement of the Jews in an increasingly Christianized Roman Palestine. Using the covenantal curses (specifically Deuteronomy 28 and Leviticus 26) as a frame, the rabbis situate the book of Esther and their current socio-political context into the rabbinic paradigm of the Four Kingdoms, representative of ongoing imperial oppression. According to Esther Rabbah, Jews living under Roman rule–even those in Palestine–are living in a state of “exile” characterized by the ongoing impact of the covenantal curses. For the rabbis, Israel cannot flourish as God’s chosen people under these exilic conditions, which will culminate in the kind of state-sanctioned annihilation of Jewry that appears in Esther. The Midrash arrives at this theo-political worldview by reading Esther as a narrative of subjugation to the covenantal curses. In presenting their current oppression as a recapitulation of the oppression suffered in Esther, the rabbis interpret the Torah’s covenantal curses as a necessary precursor to divine salvation under Rome

COMMENTS ON THE PAPER, ''EVIDENCE FOR A NEW PHASE OF SOLID sup3sup 3He''.

This report addresses the the comments on the paper "Evidence For a New Phase of Solid He$sup 3$"

Liquid and crystalline neutron matter

From sixth Texas symposium on relativistic astrophysics; New York, New York, USA (18 Dec 1972). Results of calculations of the ground-state energies of liquid and crystalline neutron matter are presented. It is found that neutron matter will crystallize at a density near normal nuclear density. This results indicates that a large fraction of the interior of a neutron star consists of crystalline neutron matter. An intuitive physical discussion is given to illuminate this result. Furthermore, it is suggested that, contrary to the usual point of view, low-density matter should be regarded as a quantum liquid'' which is almost'' a quantum crystal''. (2 figures, 1 table) (auth