Publications by authors named "Michael Rampp"

We present a comparative study on nonlinear pulse compression of 10 mJ pulses from a thin-disk amplifier at 5 kHz in a multipass cell using both gaseous and bulk nonlinear media. First, we demonstrate compressibility from 465 fs to 34 fs in an argon filled multipass cell. We then replace the nonlinear medium by bulk material and operate in vacuum.

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We present a high-energy laser source consisting of an ultrafast thin-disk amplifier followed by a nonlinear compression stage. At a repetition rate of 5 kHz, the drive laser provides a pulse energy of up to 200 mJ with a pulse duration below 500 fs. Nonlinear broadening is implemented inside a Herriott-type multipass cell purged with noble gas, allowing us to operate under different seeding conditions.

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Dual-unitary circuits are paradigmatic examples of exactly solvable yet chaotic quantum many-body systems, but solvability naturally goes along with a degree of nongeneric behavior. By investigating the effect of weakly broken dual unitarity on the spreading of local operators, we study whether, and how, small deviations from dual unitarity recover fully generic many-body dynamics. We present a discrete path-integral formula for the out-of-time-order correlator and recover a butterfly velocity smaller than the light-cone velocity, v_{B} View Article and Find Full Text PDF

Majorana zero modes are a much sought-after consequence of one-dimensional topological superconductivity. Here, we show that, in turn, zero modes accompanying dynamical instanton events strongly enhance-in some cases even enable-superconductivity. We find that the dynamics of a one-dimensional topological triplet superconductor is governed by a θ term in the action.

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We demonstrate pulse compressibility from 840 fs to 38 fs of 10 mJ pulses from a thin-disk amplifier at a repetition rate of 3 kHz after nonlinear broadening in a multipass cell. In addition, the temporal-intensity contrast is enhanced via nonlinear ellipse rotation of more than a factor 50 with an optical efficiency of 56%. We believe this is the first published experimental combination of multipass cell-based nonlinear compression and nonlinear ellipse rotation-based contrast enhancement preserving both pulse compressibility and beam quality.

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Conformational changes in proteins and peptides can be initiated by diverse processes. This raises the question how the variation of initiation mechanisms is connected to differences in folding or unfolding processes. In this work structural dynamics of a photoswitchable β-hairpin model peptide were initiated by two different mechanisms: temperature jump (T-jump) and isomerization of a backbone element.

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