Lensless imaging of atomic surface structures using ptychography in reflection mode

We propose that atomic structures on single crystal surfaces can be imaged using a variation of coherent x-ray diffractive imaging. This is a lensless ptychographic technique applied along the crystal truncation rod in reciprocal space. Simulations show that the highest sensitivity on the monolayer surface structure is obtained at the anti-Bragg condition. We demonstrate the feasibility of ptychographic reconstruction from experimental data collected in reflection mode by reconstruction of atomic steps on a crystal surface. This work and use of the Advanced Photon Source and the Electron Microscopy Center for Materials Research were supported by the U.S. Department of Energy, Office of Basic Energy Sciences, under Contract No. DE-AC02-06CH11357. The work at Safarik University is supported by Slovak grant VEGA 1/0782/12 and ERDF EU grant under contract No. ITMS 26220120005