The effect of electron-electron correlation on the attoclock experiment

We investigate multi-electron effects in strong-field ionization of Helium using a semi-classical model that, unlike other commonly used theoretical approaches, takes into account electron-electron correlation. Our approach has an additional advantage of allowing to selectively switch off different contributions from the parent ion (such as the remaining electron or the nuclear charge) and thereby investigate in detail how the final electron angle in the attoclock experiment is influenced by these contributions. We find that the bound electron exerts a significant effect on the final electron momenta distribution that can, however, be accounted for by an appropriately selected mean field. Our results show excellent agreement with other widely used theoretical models done within a single active electron approximation

Attoclock revisited on electron tunnelling time

The last decade has seen an intense renewed debate on tunnelling time, both from a theoretical and an experimental perspective. Here, we review recent developments and new insights in the field of strong-field tunnel ionization related to tunnelling time, and apply these findings to the interpretation of the attoclock experiment Landsman etal. [Optica2014, 1, 343]. We conclude that models including finite tunnelling time are consistent with recent experimental measurements.Abbreviations: A: adiabatic; ADK: Ammosov, Delone and Krainov model (1, 2); CEO: carrier-envelope-offset phase ; CoM: centre of mass;CTMC: classical trajectory monte carlo simulation; FWHM: full width half maximum; IR: infrared; KR: Keldysh-Rutherford model; NA: non-adiabatic; PMD: photoelectron momentum distribution; PPT: Perelomov, Popov and Terent'ev model (3, 4); SAE: single active electron approximation; SCT: singleclassical trajectory; SFA: strong field approximation; TDSE: time-dependent Schrodinger equatio

Exact Insulating and Conducting Ground States of a Periodic Anderson Model in Three Dimensions

We present a class of exact ground states of a three-dimensional periodic Anderson model at 3/4 filling. Hopping and hybridization of d and f electrons extend over the unit cell of a general Bravais lattice. Employing novel composite operators combined with 55 matching conditions the Hamiltonian is cast into positive semidefinite form. A product wave function in position space allows one to identify stability regions of an insulating and a conducting ground state. The metallic phase is a non-Fermi liquid with one dispersing and one flat band.Comment: 4 pages, 3 figure

Homogeneous versus Spiral Phases of Hole-doped Antiferromagnets: A Systematic Effective Field Theory Investigation

Using the low-energy effective field theory for magnons and holes -- the condensed matter analog of baryon chiral perturbation theory for pions and nucleons in QCD -- we study different phases of doped antiferromagnets. We systematically investigate configurations of the staggered magnetization that provide a constant background field for doped holes. The most general configuration of this type is either constant itself or it represents a spiral in the staggered magnetization. Depending on the values of the low-energy parameters, a homogeneous phase, a spiral phase, or an inhomogeneous phase is energetically favored. The reduction of the staggered magnetization upon doping is also investigated.Comment: 35 pages, 5 figure

Alpha-decay chains of 173288115^{288}_{173}115 and 172287115^{287}_{172}115 in the Relativistic Mean Field theory

In the recent experiments designed to synthesize the element 115 in the $^{243}$Am+$^{48}$Ca reaction at Dubna in Russia, three similar decay chains consisting of five consecutive $\alpha$-decays, and another different decay chain of four consecutive $\alpha$-decays are detected, and the decay properties of these synthesized nuclei are claimed to be consistent with consecutive $\alpha$-decays originating from the parent isotopes of the new element 115, $^{288}115$ and $^{287}115$, respectively\cite{ogan.03}. Here in the present work, the recently developed deformed RMF+BCS method with a density-independent delta-function interaction in the pairing channel is applied to the analysis of these newly synthesized superheavy nuclei $^{288}115$, $^{287}115$, and their $\alpha$-decay daughter nuclei. The calculated $\alpha$-decay energies and half-lives agree well with the experimental values and with those of the macroscopic-microscopic FRDM+FY and YPE+WS models. In the mean field Lagrangian, the TMA parameter set is used. Particular emphasis is paid on the influence to both the ground-state properties and energy surfaces introduced by different treatments of pairing. Two different effective interactions in the particle-particle channel, i.e., the constant pairing and the density-independent delta-function interaction, together with the blocking effect are discussed in detail.Comment: 17 pages, 5 figure

Zircon U-Pb Geochronology from the Wakhan Corridor, NE Afghanistan

Abstract HKT-ISTP 201

Self-consistent quantal treatment of decay rates within the perturbed static path approximation

The framework of the Perturbed Static Path Approximation (PSPA) is used to calculate the partition function of a finite Fermi system from a Hamiltonian with a separable two body interaction. Therein, the collective degree of freedom is introduced in self-consistent fashion through a Hubbard-Stratonovich transformation. In this way all transport coefficients which dominate the decay of a meta-stable system are defined and calculated microscopically. Otherwise the same formalism is applied as in the Caldeira-Leggett model to deduce the decay rate from the free energy above the so called crossover temperature $T_0$.Comment: 17 pages, LaTex, no figures; final version, accepted for publication in PRE; e-mail: [email protected]