We study the spatial decay of electron coherence due to electron-electron interaction in a finite-length disorder-free quantum wire. Based on the Luttinger liquid theory, we demonstrate that the coherence length characterizing the exponential decay of the coherence can vary from region to region, and that the coherence can even revive after the decay. This counterintuitive behavior, which is in...

Matter waves can be assigned a coherence length analogous to the corresponding quantity in optics. We show that there is a dramatic increase in coherence length associated with the appearance of Bose–Einstein condensation in a trapped ideal Bose gas. The large increase in coherence length occurs even for temperatures just below the critical temperature at which only a small proportion of the tr...

We describe the spatial coherence properties of a cold atom electron source in the framework of a quasihomogeneous wavefield. The model is used as the basis for direct measurements of the transverse spatial coherence length of electron bunches extracted from a cold atom electron source. The coherence length is determined from the measured visibility of a propagated electron distribution with a ...

A Mach-Zehnder interferometer with spatial and spectral resolution was used to probe spontaneous coherence in cold exciton gases, which are implemented experimentally in the ring of indirect excitons in coupled quantum wells. A strong enhancement of the exciton coherence length is observed at temperatures below a few Kelvin. The increase of the coherence length is correlated with the macroscopi...

We report an experimental demonstration of optical coherence tomography for transmissive objects utilizing second-order correlation ghost imaging with thermal light. To evaluate the longitudinal resolution of our system, the concept of the imaging longitudinal coherence length is introduced, which is more accurate for judging the image quality of ghost imaging with unequal optical paths than th...