A unique quasi-probability for projective yes-no measurements

Sequential projective measurements for channel decoding

We study the transmission of classical information in quantum channels. We present a decoding procedure that is very simple but still achieves the channel capacity. It is used to give an alternative straightforward proof that the classical capacity is given by the regularized Holevo bound. This procedure uses only projective measurements and is based on successive "yes"/"no" tests only.

Quantum Quasi-Zeno Dynamics: Transitions mediated by frequent projective measurements near the Zeno regime

Frequent observation of a quantum system leads to quantum Zeno physics, where the system evolution is constrained to states commensurate with the measurement outcome. We show that, more generally, the system can evolve between such states through higher-order virtual processes that pass through states outside the measurement subspace. We derive effective Hamiltonians to describe this evolution, and the dependence on the time between measurements. We demonstrate application of this phenomena to prototypical quantum many-body system examples, spin chains and atoms in optical lattices, where it f…

Interferometry versus projective measurement of anyons

The distinct methods for measuring topological charge in a non-abelian anyonic system have been discussed in the literature: projective measurement of a single point-like quasiparticle and interferometric measurement of the total topological charge of a group of quasiparticles. Projective measurement by definition is only applied near a point and will project to a topological charge sector near that point. Thus, if it is to be applied to a \emph{group} of anyons to project to a \emph{total} charge, then the anyons must first be fused one by one to obtain a single anyon carrying the collective …

投影测量可探测非经典功提取与时间关联

Projective measurements can probe non-classical work extraction and time-correlations

本研究提出无需辅助系统的投影测量技术表征非经典多时间关联，在金刚石氮-空位中心实验中观测到五倍于常规方案的功提取峰值，并用准概率负性的反常能量交换解释该现象。