In the past decade, the toolkit of quantum information has been expanded to include
processes in which the basic operations do not have definite causal relations. Originally …

This tutorial introduces a systematic approach for addressing the key question of quantum
metrology: For a generic task of sensing an unknown parameter, what is the ultimate …

The Heisenberg limit [(HL), with estimation error scales as 1/n] and the standard quantum
limit (SQL,∝ 1/n) are two fundamental limits in estimating an unknown parameter in n copies …

We derive new bounds on achievable precision in the most general adaptive quantum
metrological scenarios. The bounds are proven to be asymptotically saturable and …

In quantum metrology, one of the major applications of quantum technologies, the ultimate
precision of estimating an unknown parameter is often stated in terms of the Cram\'er-Rao …

A crucial yet challenging issue in quantum metrology is to ascertain the ultimate precision
achievable in estimation strategies. While there are two paradigms of estimations, local and …

The ultimate precision in quantum sensing could be achieved using optimal quantum probe
states. However, current quantum sensing protocols do not use probe states optimally …

Measurement noise is a major source of noise in quantum metrology. Here, we explore
preprocessing protocols that apply quantum controls to the quantum sensor state prior to the …

Using quantum systems as sensors or probes has been shown to greatly improve the
precision of parameter estimation by exploiting unique quantum features such as …

Quantum theory allows the traversing of multiple channels in a superposition of different
orders. When the order in which the channels are traversed is controlled by an auxiliary …