Quantum information theory is a branch of science at the frontier of physics, mathematics,
and information science, and offers a variety of solutions that are impossible using classical …

Many protocols require precise rotation measurement. Here we present a general class of
states that surpass the shot-noise limit for measuring rotation around arbitrary axes. We then …

A construction of genuinely entangled multipartite quantum states based on the group theory
is presented. Analyzed states resemble the Dicke states, whereas the interactions occur only …

It is often thought that the super-sensitivity of a quantum state to an observable comes at the
cost of a decreased sensitivity to other non-commuting observables. For example, a …

Coherent and anticoherent states of spin systems up to spin $ j= 2$ are known to be optimal
in order to detect rotations by a known angle but unknown rotation axis. These optimal …

Spin anticoherent states acquired recently a lot of attention as the most" quantum" states.
Some coherent and anticoherent spin states are known as optimal quantum rotosensors. In …

The opportunity to build quantum technologies operating with elementary quantum systems
with more than two levels is now increasingly being examined, not least because of the …

Spin states of maximal projection along some direction in space are called (spin) coherent,
and are, in many respects, the'most classical'available. For any spin s, the spin coherent …

When some of the parties of a multipartite entangled pure state are lost, the question arises
whether the residual mixed state is also entangled, in which case the initial entangled pure …

A constellation of N= d− 1 Majorana stars represents an arbitrary pure quantum state of
dimension d or a permutation-symmetric state of a system consisting of n qubits. We …