Directed excitation transfer in vibrating chains by external fields

Phase directed excitonic transport and its limitations due to environmental influence

We investigate theoretically the transfer of excitation along a one dimensional chain of monomers for a situation in which initially the excitation is shared coherently by two monomers. We show that depending on the relative phase between the two monomers strong directionality of the energy transfer is possible. It is also investigated how dephasing, induced by an environment, influences this directed transport.

Hamiltonian chaos in a coupled BEC -- optomechanical cavity system

We study a hybrid optomechanical system consisting of a Bose-Einstein condensate (BEC) trapped inside a single-mode optical cavity with a moving end-mirror. The intracavity light field has a dual role: it excites a momentum side-mode of the condensate, and acts as a nonlinear spring that couples the vibrating mirror to that collective density excitation. We present the dynamics in a regime where the intracavity optical field, the mirror, and the side-mode excitation all display bistable behavior. In this regime we find that the dynamics of the system exhibits Hamiltonian chaos for appropriate …

Collective excitations in graphene in magnetic field

Collective excitations in graphene monolayer are studied. Equations describing collective properties of electrons in graphene are obtained. The basic ideas of the method of many-particle quantum hydrodynamics are used for the derivation. As starting point of the derivation we use the Dirac equation for massless electrons which is usually used for description of electrons in graphene [D. E. Sheehy and J. Schmalian, Phys. Rev. Lett. 99, 226803 (2007)], where the Coulomb interaction is taken into account. We study dispersion properties of collective excitations by means derived here graphene quan…

Spectroscopy and Directed Transport of Topological Solitons in Crystals of Trapped Ions

We study experimentally and theoretically discrete solitons in crystalline structures consisting of several tens of laser-cooled ions confined in a radiofrequency trap. Resonantly exciting localized, spectrally gapped vibrational modes of the soliton, a nonlinear mechanism leads to a nonequilibrium steady state of the continuously cooled crystal. We find that the propagation and the escape of the soliton out of its a quasi-one-dimensional channel can be described as a thermal activation mechanism. We control the effective temperature of the soliton's collective coordinate by the amplitude of t…

氟苯中电子波包电离与激发时的阿托化学量子干涉特征

Signature of attochemical quantum interference upon ionization and excitation of an electronic wavepacket in fluoro-benzene

本研究量子力学全维模拟了苯和氟苯电离至不同电子波包后的耦合电子-核动力学，揭示了氟苯中影响自相关函数的态间与态内量子干涉，其阿托化学特征与实验高次谐波光谱一致。

动态网络上里德伯激发传播的非平衡普适性

Nonequilibrium Universality of Rydberg-Excitation Spreading on a Dynamic Network

本文结合冷$^{87}$Rb实验与数值模拟，利用雪崩分布刻画动态原子网络中里德伯激发传播的吸收态相变，并揭示耗散强度对DP至MF普适类渡越的影响。