  We present a search for a light sterile neutrino using three years of
atmospheric neutrino data from the DeepCore detector in the energy range of
approximately $10-60~$GeV. DeepCore is the low-energy sub-array of the IceCube
Neutrino Observatory. The standard three-neutrino paradigm can be probed by
adding an additional light ($\Delta m_{41}^2 \sim 1 \mathrm{\ eV^2}$) sterile
neutrino. Sterile neutrinos do not interact through the standard weak
interaction, and therefore cannot be directly detected. However, their mixing
with the three active neutrino states leaves an imprint on the standard
atmospheric neutrino oscillations for energies below 100 GeV. A search for such
mixing via muon neutrino disappearance is presented here. The data are found to
be consistent with the standard three neutrino hypothesis. Therefore we derive
limits on the mixing matrix elements at the level of $|U_{\mu4}|^2 < 0.11 $ and
$|U_{\tau4}|^2 < 0.15 $ (90% C.L.) for the sterile neutrino mass splitting
$\Delta m_{41}^2 = 1.0$ eV$^2$.
