Figure 1

(a) Schematic depicting the quantum interference of one- and two-photon pathways between the valence and conduction bands in LT-GaAs. Coherent control of the injected photocurrent is obtained using an octave spanning spectrum with a controlled carrier-envelope phase slip. (b) The carrier-envelope phase change between pulses evolves at a defined rate, $f_0=1/T$.Reuse & Permissions

Figure 2

Experimental setup used for quantum interference control of injected photocurrents in LT-GaAs. The laser offset frequency is measured using a $\nu$-to-$2\nu$ interferometer and stabilized via negative feedback to the laser. Microstructure fiber is used for external broadening of the Ti:S laser spectrum for stabilization and QIC characterization. Because of fiber dispersion, a prism sequence for time delay compensation and a split mirror after the second prism are used for spectral filtering. Light at $\nu$ and $2\nu$ are $p$ polarized such that the electric field oscillates transversely along the axis between the two gold electrodes on the LT-GaAs sample (inset).Reuse & Permissions

Figure 3

(a) Spectrum of the measured QIC signal (10 Hz bandwidth, 100 averages). The linewidth (resolution limited) of the measured QIC signal indicates the stability of the laser offset frequency. The dotted and solid gray lines show the QIC signals corresponding to the optical spectra in (b). The solid black line gives the case when the light is blocked. (b) The dip at $\sim 500\mathrm{nm}$ corresponds to unavoidable optical filtering due to the small gap between the split mirrors in Fig. 2.Reuse & Permissions

Figure 4

(a) Phase of the QIC signal as measured relative to the reference used for laser stabilization. The time record of the QIC phase (100 ms time constant) shows the phase jumps associated with rotations of the glass plate from 0° to $\theta$ and back again for eight different rotation angles. (b) Comparison between the phase change measured in (a) (squares) and the calculated carrier-envelope phase change (dashed line).Reuse & Permissions