  Conduction of electrons in matter is ultimately described by quantum
mechanics. Yet at low frequency or long time scales, low temperature quantum
transport is perfectly described by this very simple idea: electrons are
emitted by the contacts into the sample which they may cross with a finite
probability. Combined with Fermi statistics, this partition of the electron
flow accounts for the full statistics of electron transport. When it comes to
short time scales, a key question must be clarified: are there correlations
between successive attempts of the electrons to cross the sample? While there
are theoretical predictions and several experimental indications for the
existence of such correlations, no direct experimental evidence has ever been
provided. Here we show a direct experimental proof of how temperature and
voltage bias control the electron flow: while temperature $T$ leads to a jitter
which tends to decorrelate electron transport after a time $\hbar/k_BT$, the
bias voltage $V$ induces strong correlations/anticorrelations which oscillate
with a period $h/eV$. Our experiment reveals how time scales related to voltage
and temperature operate on quantum transport in a coherent conductor. In
complex quantum systems, the method we have developed might offer direct access
to other relevant time scales related, for example, to internal dynamics,
coupling to other degrees of freedom, or correlations between electrons.
