Coherent control of attosecond emission from aligned molecules

Controlling attosecond electron wave packets and soft X-ray pulses represents a formidable challenge of general implication to many areas of science(1-4). A strong laser field interacting with atoms or molecules drives ultrafast intra-atomic/molecular electron wave packets on a subfemtosecond timescale, resulting in the emission of attosecond bursts of extreme-ultraviolet light(5,6). Controlling the intra-atomic/molecular electron dynamics enables steering of the attosecond emission(7,8). Here, we carry out a coherent control in linear molecules, where the interaction of the laser-driven electron wave packet with the core leads to quantum interferences(9-12). We demonstrate that these interferences can be finely controlled by turning the molecular axis relative to the laser polarization, that is, changing the electron recollision angle. The wave-packet coulombic distortion modifies the spectral phase jump measured in the extreme-ultraviolet emission. Our attosecond control of the interference results in attosecond pulse shaping, useful for future applications in ultrafast coherent control of atomic and molecular processes.