The interaction of few-cycle laser pulses with a nanometric metal tip is described. We find many effects that the strong-field physics community has discovered with atoms in the last 30 years, and describe them here in experiments with solid nanotips. Starting with a clear identification of several photon orders in above-threshold photoemission, via strong-field effects such as peak shifting and peak suppression, to the observation of a pronounced plateau in electron spectra, we show that we have reached the level of control necessary for attosecond physics experiments. In particular, we observe electronic wavepacket dynamics on the attosecond time scale. Namely, by variation of the carrier-envelope phase of the driving laser pulses, we observe a qualitative change in the electron spectra: For cosine pulses we obtain an almost flat plateau part, whereas for minus-cosine pulses the plateau part clearly shows photon orders. We interpret this change by the occurrence of a single or a double slit configuration in time causing electronic matter wave interference in the time-energy domain.

We demonstrate the transverse confinement and guiding of a low energy electron beam of several electron volts in a miniaturized linear quadrupole guide. The guiding potential is generated by applying a microwave voltage to electrodes fabricated on a planar substrate, which allows the potential landscape to be precisely shaped on a microscopic scale. We realize transverse trapping frequencies of 100 MHz and guide electrons along a circular section of 37 mm length. A detailed characterization of the guiding properties in terms of potential depth and dynamic stability is given. This new technique of electron guiding promises various applications in guided matter-wave experiments such as electron interferometry.

We present microwave electrode structures suited for guiding electrons propagating in a purely electric, alternating quadrupole field. In a first experiment using a standing wave on an electrically short structure, we previously demonstrated the general concept of electron confinement in microwave fields. Here, we discuss the extension to electrically long structures supporting travelling microwave excitations. This requires a modal decomposition of the voltage patterns on the multiconductor transmission line formed by the electrodes. We show that the use of a general five-wire structure leads to the distortion of the guiding potential upon propagation due to differing modal propagation constants. This can be avoided by implementing a coupled microstrip configuration with elevated signal electrodes. With structures like these, complex geometries connecting different beam manipulation elements can be realized, enabling new forms of electron experiments with guided matter waves.

The paper presents the numerical modelling results and first experimental steps on an experiment aiming at guiding electrons in an AC quadrupole guide. In the proposed setup, electrons originating from a sharp tungsten field emission source is focused by means of a suitable electron-lens system into a linear Paul-trap operating at microwave frequencies. The control over the electrons' motional degrees of freedom gained in this way would allow e.g. for interference experiments with guided electrons or the deterministic interaction of two counterpropagating electrons.

The authors report on a single-pass amplifier for broadband Ti:sapphire femtosecond laser pulses. The authors observe a gain of up ~4 for 100fs pulses and 2.6 for ~7fs pulses. The authors also report on the measurement of phase jitter added by the amplifier onto the frequency comb due to the amplification process [the amplifier project is in collaboration with A. Ozawa, W. Schneider, Th. Udem and T.W. Hansen].

Sharp metal tips as field emitters are well-known and established electron sources. A DC-electric field leads to a continuous electron tunnel current out of the high-energy tail of the electron thermal distribution. In contrast in this paper, the authors present a project where electrons are emitted due to the high electric field delivered by ultrashort laser pulses.

Microwave near-fields are a key ingredient for quantum information processing with atom chips. Our goal is to realize a quantum gate with the following features: the qubit is encoded in the hyperfine states |1rang equiv |F=1, mF=-1rang and |2rang equiv |F=2, mF=+1rang of 87Rb, which are both magnetically trappable and allow for very long coherence lifetimes. Microwave near-fields guided on the atom chip are used to drive single-qubit rotations and provide state-selectivity to the magnetic trapping potential. The quantum phase gate is implemented by state-selective collisions of two qubit atoms in this potential. Besides applications in quantum information processing, microwave near-fieIds on atom chips can also be used for atom interferometry and chip-based atomic clocks.