  Single pulses preserve information about the pulsar radio emission and
propagation in the pulsar magnetosphere, and understanding the behaviour of
their variability is essential for estimating the fundamental limit on the
achievable pulsar timing precision. Here we report the findings of our analysis
of single pulses from PSR J1713+0747 with data collected by the Large European
Array for Pulsars (LEAP). We present statistical studies of the pulse
properties that include distributions of their energy, phase and width. Two
modes of systematic sub-pulse drifting have been detected, with a periodicity
of 7 and 3 pulse periods. The two modes appear at different ranges of pulse
longitude but overlap under the main peak of the integrated profile. No
evidence for pulse micro-structure is seen with a time resolution down to 140
ns. In addition, we show that the fractional polarisation of single pulses
increases with their pulse peak flux density. By mapping the probability
density of linear polarisation position angle with pulse longitude, we reveal
the existence of two orthogonal polarisation modes. Finally, we find that the
resulting phase jitter of integrated profiles caused by single pulse
variability can be described by a Gaussian probability distribution only when
at least 100 pulses are used for integration. Pulses of different flux
densities and widths contribute approximately equally to the phase jitter, and
no improvement on timing precision is achieved by using a sub-set of pulses
with a specific range of flux density or width.
