01507nas a2200169 4500008003700000020002400037245009600061210006900157260006000226300001600286520090900302100001801211700002101229700001901250700002001269856004801289 0 d a{978-1-5386-4781-3}00a{Fully Quantum Arbitrarily Varying Channels: Random Coding Capacity and Capacity Dichotomy}0 aFully Quantum Arbitrarily Varying Channels Random Coding Capacit b{IEEE; IEEE Informat Theory Soc; NSF; Huawei; Qualcomm} a{2012-2016}3 a{We consider a model of communication via a fully quantum jammer channel with quantum jammer, quantum sender and quantum receiver, which we dub quantum arbitrarily varying channel (QAVC). Restricting to finite dimensional user and jammer systems, we show, using permutation symmetry and a de Finetti reduction, how the random coding capacity (classical and quantum) of the QAVC is reduced to the capacity of a naturally associated compound channel, which is obtained by restricting the jammer to i.i.d. input states. Furthermore, we demonstrate that the shared randomness required is at most logarithmic in the block length, via a quantum version of the ``elimination of of correlation{''} using a random matrix tail bound. This implies a dichotomy theorem: either the classical capacity of the QAVC is zero, and then also the quantum capacity is zero, or each capacity equals its random coding variant.}1 aBoche, Holger1 aDeppe, Christian1 aNoetzel, Janis1 aWinter, Andreas uhttps://grupsderecerca.uab.cat/giq/node/924