Abstract The worldline formalism provides an alternative to Feynman diagrams that has been found particularly useful for external-field calculations in quantum electrodynamics. Here I summarize its present range of applications, which includes Schwinger pair creation, photon splitting constant fields and plane-wave backgrounds, as well non-linear Compton scattering fields.

We investigate the discrete orbital angular momentum (OAM) of photoelectrons freed in strongfield ionization. use these `twisted' electrons to provide an alternative interpretation on existing experimental work vortex interferences caused by strong field ionization mediated two counterrotating circularly polarized pulses separated a delay. Using approximation, we derive interference condition f...

Ionization of an atom or molecule by a strong laser field produces suboptical cycle wave packets whose control has given rise to attosecond science. The final states of the wave packets depend on ionization and deflection by the laser field, which are convoluted in conventional experiments. Here, we demonstrate a technique enabling efficient electron deflection, separate from the field driving ...

We present the observational results of a survey for strong gravitational lens systems consisting of extended emission-line galaxies lensed by intervening earlytype galaxies, conducted using integral field units (IFUs) of the Magellan IMACS and Gemini GMOS-N spectrographs. These data are highly valuable for corroborating the lensing interpretation of Hubble Space Telescope imaging data. We show...

Using the recently proposed density matrix renormalization group technique [1] we show that the magnons in the S = 1 antiferromagnetic Heisenberg chain effectively behaves as bosons that condense at a critical field hc. We determine the spin-wave velocity, v = 2.49(1), as well as the gap ∆ = 0.4107(1)J . 75.10.-b, 75.10.Jm, 75.40.Mg Typeset using REVTEX 1 It is by now well established both expe...

We present a numerical method for investigating the non-perturbative quantum mechanical interaction of light with atoms in two dimensions, without a basis expansion. This enables us to investigate intense laser-atom interactions with light of arbitrary polarization without approximation. Results are presented for the dependence of ionization and high harmonic generation on ellipticity seen in r...