Waiting Times and Noise in Single Particle Transport

The waiting time distribution $w(\tau)$, i.e. the probability for a delay $\tau$ between two subsequent transition (`jumps') of particles, is a statistical tool in (quantum) transport. Using generalized Master equations for systems coupled to external particle reservoirs, one can establish relations between $w(\tau)$ and other statistical transport quantities such as the noise spectrum and the Full Counting Statistics. It turns out that $w(\tau)$ usually contains additional information on system parameters and properties such as quantum coherence, the number of internal states, or the entropy of the current channels that participate in transport

Time delayed control of excited state quantum phase transitions in the Lipkin-Meshkov-Glick model

We investigate the role of dissipation in excited state quantum phase transitions (ESQPT) within the Lipkin-Meshkov-Glick model. Signatures of the ESQPT are directly visible in the complex spectrum of an effective Hamiltonian, whereas they get smeared out in the time-dependence of system observables. In the latter case, we show how delayed feedback control can be used to restore the visibility of the ESQPT signals

IMF's assistance: Devil's kiss or guardian angel?

This paper contributes to the debate on the efficacy of IMF's catalytic finance in preventing financial crises. Extending Morris and Shin (2006), we consider that the IMF's intervention policy usually exerts a signaling effect on private creditors and that several interventions in sequence may be necessary to avert an impending crisis. Absent of the IMF's signaling ability, our results state that repeated intervention is required to bail out a country, where by additional assistance may induce moral hazard on the debtor side. Contrarily, if the IMF exerts a strong signaling effect, one single intervention suffices to avoid liquidity crises. --catalytic finance,debtor moral hazard,global games