  We present the discovery of a brown dwarf companion to the debris disk host
star HR 2562. This object, discovered with the Gemini Planet Imager (GPI), has
a projected separation of 20.3$\pm$0.3 au (0.618$\pm$0.004") from the star.
With the high astrometric precision afforded by GPI, we have confirmed common
proper motion of HR 2562B with the star with only a month time baseline between
observations to more than $5\sigma$. Spectral data in $J$, $H$, and $K$ bands
show morphological similarity to L/T transition objects. We assign a spectral
type of L7$\pm$3 to HR 2562B, and derive a luminosity of $\log$(L$_{\rm
bol}$/L$_{\odot}$)=-4.62$\pm$0.12, corresponding to a mass of 30$\pm$15 M$_{\rm
Jup}$ from evolutionary models at an estimated age of the system of 300-900
Myr. Although the uncertainty in the age of the host star is significant, the
spectra and photometry exhibit several indications of youth for HR 2562B. The
source has a position angle consistent with an orbit in the same plane as the
debris disk recently resolved with Herschel. Additionally, it appears to be
interior to the debris disk. Though the extent of the inner hole is currently
too uncertain to place limits on the mass of HR 2562B, future observations of
the disk with higher spatial resolution may be able to provide mass
constraints. This is the first brown dwarf-mass object found to reside in the
inner hole of a debris disk, offering the opportunity to search for evidence of
formation above the deuterium burning limit in a circumstellar disk.
