arXiv subjects

H. Müller

Publications and source records attributed to H. Müller.

22 records · Page 2Linked to original sources

arXiv2005

Angle-dependent magnetoresistance in the weakly incoherent interlayer transport regime

We present comparative studies of the orientation effect of a strong magnetic field on the interlayer resistance of $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$ samples characterized by different crystal quality. We find striking differences in their behavior which is attributed to the breakdown of the coherent charge transport across the layers in the lower quality sample. In the latter case, the nonoscillating magnetoresistance background is essentially a function of only the out-of-plane field component, in contradiction to the existing theory.

cond-mat.str-el↗

arXiv2005

The Search for Quantum Gravity Signals

We give an overview of ongoing searches for effects motivated by the study of the quantum-gravity problem. We describe in greater detail approaches which have not been covered in recent ``Quantum Gravity Phenomenology'' reviews. In particular, we outline a new framework for describing Lorentz invariance violation in the Maxwell sector. We also discuss the general strategy on the experimental side as well as on the theoretical side for a search for quantum gravity effects. The role of test theories, kinematical and dymamical, in this general context is emphasized. The present status of controlled laboratory experiments is described, and we also summarize some key results obtained on the basis of astrophysical observations.

gr-qc↗

arXiv2002

Proton--induced deuteron breakup at GeV energies with forward emission of a fast proton pair

A study of the deuteron breakup reaction $pd \to (pp)n$ with forward emission of a fast proton pair with small excitation energy $E_{pp}<$ 3 MeV has been performed at the ANKE spectrometer at COSY--Jülich. An exclusive measurement was carried out at six proton--beam energies $T_p=$~0.6,~0.7,~0.8,~0.95,~1.35, and 1.9 GeV by reconstructing the momenta of the two protons. The differential cross section of the breakup reaction, averaged up to $8^{\circ}$ over the cm polar angle of the total momentum of the $pp$ pairs, has been obtained. Since the kinematics of this process is quite similar to that of backward elastic $pd \to dp$ scattering, the results are compared to calculations based on a theoretical model previously applied to the $pd \to dp$ process.

nucl-ex↗

arXiv2001

Orbital effect of a magnetic field on the low temperature state in the organic metal $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$

The effect of pressure on the B--T phase diagram of $α$-(BEDT-TTF)$_2$KHg(SCN)$_4$ is studied. The measured phase lines can be well described by a recent model of a charge-density wave system with varying nesting conditions. A remarkable increase of the transition temperature with magnetic field is found in a certain pressure and field range. We associate this result with a dramatic enhancement of the orbital effect of magnetic field due to a deterioration of the nesting conditions by pressure. Furthermore, we present data which can be interpreted as a first sign of field-induced charge-density waves.

cond-mat.str-el↗