Continuous decomposition of quantum measurements via Hamiltonian feedback
Continuous decomposition of quantum measurements via Hamiltonian feedback
复制标题
通过哈密顿反馈连续分解量子测量
DOI：
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发表时间：
2015
期刊：
影响因子：
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通讯作者：
T. Brun
中科院分区：
文献类型：
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作者：
Jan Florjanczyk;T. Brun
南加州大学洛杉矶分校电子工程系通信科学研究所量子信息科学与技术中心，CA 90089（日期：2015年4月16日）我们描述了一组广义量子测量，这些测量可以用探测量子位流和可调谐的相互作用哈密尔年分解为连续的测量过程。流中的每个探针与目标量子系统弱相互作用，然后在标准基础上进行投影测量。该测量结果用于封闭反馈回路，以调谐下一个探针的相互作用哈密顿量。由此产生的进化是一个具有一维随机游走结构的随机过程。为了保持这种结构，并要求测量结果在很长时间内与路径无关，允许的相互作用哈密顿量必须位于一个限制集中，这样目标系统上的哈密顿量项就形成了一个一维的约当代数。这种相互作用哈密顿量的代数结构产生了一大类可由我们的方案连续执行的广义测量，并充分描述了这一集合。
Center for Quantum Information Science and Technology,Communication Sciences Institute, Department of Electrical Engineering,University of Southern California Los Angeles, CA 90089, USA.(Dated: April 16, 2015)We characterize the set of generalized quantum measurements that can be decomposed into acontinuous measurement process using a stream of probe qubits and a tunable interaction Hamilto-nian. Each probe in the stream interacts weakly with the target quantum system, then is measuredprojectively in a standard basis. This measurement result is used in a closed feedback loop to tunethe interaction Hamiltonian for the next probe. The resulting evolution is a stochastic process withthe structure of a one-dimensional random walk. To maintain this structure, and require that atlong times the measurement outcomes be independent of the path, the allowed interaction Hamil-tonians must lie in a restricted set, such that the Hamiltonian terms on the target system form a nite dimensional Jordan algebra. This algebraic structure of the interaction Hamiltonians yields alarge class of generalized measurements that can be continuously performed by our scheme, and wefully describe this set.