Wolf Michael M, Pérez-García David, Giedke Geza
Max-Planck-Institute for Quantum Optics, Hans-Kopfermann-Strasse 1, D-85748 Garching, Germany.
Phys Rev Lett. 2007 Mar 30;98(13):130501. doi: 10.1103/PhysRevLett.98.130501. Epub 2007 Mar 26.
We investigate the capacity of bosonic quantum channels for the transmission of quantum information. We calculate the quantum capacity for a class of Gaussian channels, including channels describing optical fibers with photon losses, by proving that Gaussian encodings are optimal. For arbitrary channels we show that achievable rates can be determined from few measurable parameters by proving that every channel can asymptotically simulate a Gaussian channel which is characterized by second moments of the initial channel. Along the way we provide a complete characterization of degradable Gaussian channels and those arising from teleportation protocols.
我们研究了用于量子信息传输的玻色子量子信道的容量。通过证明高斯编码是最优的，我们计算了一类高斯信道的量子容量，包括描述具有光子损耗的光纤的信道。对于任意信道，我们证明每个信道都可以渐近地模拟一个由初始信道的二阶矩表征的高斯信道，从而表明可实现的速率可以由少数可测量的参数确定。在此过程中，我们对可降解高斯信道以及那些由隐形传态协议产生的信道进行了完整的表征。
