Single top quark production at the Tevatron

The observation of single top quark production by the CDF and D0 collaborations is one of the flagship measurements of the Run II of the Tevatron. The Tevatron combined single top quark cross section is measured to be: $\sigma(tb+X,~tqb+X)=2.8^{+0.6}_{-0.5}$~pb for a top quark mass of 170~GeV. This result is in agreement with the standard model production of a single top quark together with a jet in $\ppbar$ collisions at $\sqrt{s}$=1.96~TeV and allows to measure the CKM matrix element $|V_{tb}|$ without assumptions about the number of quark families. Other analyses involving tau leptons have been performed, and several properties, like the top quark width or the polarization have been measured.