, many of which can only be realized by confining graphene into nanoribbons and other nanostructures. For example, ballistic room-temperature transistors 3-5 and carbon-based spintronic devices 6-10 are two tantalizing possibilities which could one day be realized in a graphene nanodevice. First though, a reliable method must be found to controllably produce graphene nanostructures with specific sizes, geometries, and defined crystallographic edges. Theoretical predictions indicate that a graphene nanoribbon with zig-zag edges can behave as a half-metal 6, 7 which, paired with graphene's long spin relaxation time 11 , could be used to produced spin-valves and other spintronic devices. In addition, nanosized geometric structures such as triangles with zig-zag edges are predicted to have a net nonzero spin 8,9,12, 13 , furthering the potential use of graphene as a canvas for spintronic circuits. For field effect transistor applications, quantum confinement induces a band gap in the normally gapless graphene 10,14,15 , but the potential performance of the device depends strongly on the edge structure as well 4,16,17 . . Indeed, previous studies of catalytic gasification of carbon found that catalytic metal nanoparticles would sometimes etch graphite along crystallographic directions, creating both armchair and zigzag edges [27][28][29][30][31] .

We investigated electron-beam lithography with an aberration-corrected scanning transmission electron microscope. We achieved 2 nm isolated feature size and 5 nm half-pitch in hydrogen silsesquioxane resist. We also analyzed the resolution limits of this technique by measuring the point-spread function at 200 keV. Furthermore, we measured the energy loss in the resist using electron-energy-loss spectroscopy.

One of the astounding consequences of quantum mechanics is that it allows the detection of a target using an incident probe, with only a low probability of interaction of the probe and the target. This 'quantum weirdness' could be applied in the field of electron microscopy to generate images of beam-sensitive specimens with substantially reduced damage to the specimen. A reduction of beam-induced damage to specimens is especially of great importance if it can enable imaging of biological specimens with atomic resolution. Following a recent suggestion that interaction-free measurements are possible with electrons, we now analyze the difficulties of actually building an atomic resolution interaction-free electron microscope, or "quantum electron microscope". A quantum electron microscope would require a number of unique components not found in conventional transmission electron microscopes. These components include a coherent electron beam-splitter or two-state-coupler, and a resonator structure to allow each electron to interrogate the specimen multiple times, thus supporting high success probabilities for interaction-free detection of the specimen. Different system designs are presented here, which are based on four different choices of two-state-couplers: a thin crystal, a grating mirror, a standing light wave and an electro-dynamical pseudopotential. Challenges for the detailed electron optical design are identified as future directions for development. While it is concluded that it should be possible to build an atomic resolution quantum electron microscope, we have also identified a number of hurdles to the development of such a microscope and further theoretical investigations that will be required to enable a complete interpretation of the images produced by such a microscope.