arXiv subjects

Christoph Schick

Publications and source records attributed to Christoph Schick.

3 recordsLinked to original sources

arXiv2026

Highly Stable Glasses of cis-Decalin and cis/trans-Decalin Mixtures

In situ AC nanocalorimetry was used to measure the reversing heat capacity of vapor-deposited glasses of decahydronaphthalene (decalin). Glasses with low heat capacity and high kinetic stability, as compared to the corresponding liquid-cooled glass, were prepared from cis-decalin and from several cis/trans-decalin mixtures. This is the first report of highly stable glass formation for molecular mixtures. The 50/50 cis/trans-decalin mixture is the highest fragility material reported to produce an ultrastable glass. The 50/50 mixture exhibited high kinetic stability, with an ~500 nm film deposited at 116 K (0.86 Tg,) displaying a transformation time equivalent to 104.4 times the structural relaxation time of the supercooled liquid at the annealing temperature. Cis-decalin and the decalin mixture formed stable glasses that had heat capacities as much as 4.5% lower than the liquid-cooled glass.

cond-mat.soft↗

arXiv2026

One micron length scale controls kinetic stability of low energy glasses

AC nanocalorimetry was used to measure the reversing heat capacity Cp of low energy indomethacin glasses as they isothermally transform into the supercooled liquid. As the film thickness increases from 75 to 600 nm, the transformation time increases by more than an order of magnitude, consistent with a surface-initiated transformation mechanism. Eventually, the transformation time becomes constant for films between 1.4 and 30 microns indicating a distinct bulk transformation pathway. The observation of size-dependent transformation kinetics for glass samples approaching 1 micron is unprecedented. We interpret the crossover in thickness dependence at 1 micron to signify the average distance between transformation initiation sites in the bulk low energy glass.

cond-mat.soft↗

arXiv2014

D7-Brane Moduli Space in Axion Monodromy and Fluxbrane Inflation

We analyze the quantum-corrected moduli space of D7-brane position moduli with special emphasis on inflationary model building. D7-brane deformation moduli are key players in two recently proposed inflationary scenarios: The first, D7-brane chaotic inflation, is a variant of axion monodromy inflation which allows for an effective 4d supergravity description. The second, fluxbrane inflation, is a stringy version of D-term hybrid inflation. Both proposals rely on the fact that D7-brane coordinates enjoy a shift-symmetric Kahler potential at large complex structure of the Calabi-Yau threefold, making them naturally lighter than other fields. This shift symmetry is inherited from the mirror-dual Type IIA Wilson line on a D6-brane at large volume. The inflaton mass can be provided by a tree-level term in the flux superpotential. It induces a monodromy and, if tuned to a sufficiently small value, can give rise to a large-field model of inflation. Alternatively, by a sensible flux choice one can completely avoid a tree-level mass term, in which case the inflaton potential is induced via loop corrections. The positive vacuum energy can then be provided by a D-term, leading to a small-field model of hybrid natural inflation. In the present paper, we continue to develop a detailed understanding of the D7-brane moduli space focusing among others on shift-symmetry-preserving flux choices, flux-induced superpotential in Type IIB/F-theory language, and loop corrections. While the inflationary applications represent our main physics motivation, we expect that some of our findings will be useful for other phenomenological issues involving 7-branes in Type IIB/F-theory constructions.

hep-th↗