115 citations · 298 across the 18 of their papers we have counts for
19 papers
Generalised contextuality of continuous variable quantum theory can be revealed with a single projective measurement
Pauli Jokinen, Mirjam Weilenmann, Martin Plávala +3
Generalized contextuality is a possible indicator of non-classical behaviour in quantum information theory. In finite-dimensional systems, this is justified by the fact that noncon…
Incompatible measurements in quantum information science
Otfried Gühne, Erkka Haapasalo, Tristan Kraft +2
Some measurements in quantum mechanics disturb each other. This has puzzled physicists since the formulation of the theory, but only in recent decades has the incompatibility of me…
Optimal quantum observables
Erkka Haapasalo, Juha-Pekka Pellonpaa
Various forms of optimality for quantum observables described as normalized positive operator valued measures (POVMs) are studied in this paper. We give characterizations for obser…
Covariant KSGNS construction and quantum instruments
Erkka Haapasalo, Juha-Pekka Pellonpää
We study positive kernels on , where is a set equipped with an action of a group, and taking values in the set of -sesquilinear forms on a (not necessari…
On coexistence and joint measurability of rank-1 quantum observables
Juha-Pekka Pellonpää
We show that a rank-1 quantum observable (POVM) M is jointly measurable with a quantum observable M' exactly when M' is a smearing of M. If M is extreme, rank-1 and discrete then M…
On measurements of the canonical phase observable
Juha-Pekka Pellonpää, Jussi Schultz
Measurements of single-mode phase observables are studied in the spirit of the quantum theory of measurement. We determine the minimal measurement models of phase observables and c…
Complete quantum measurements break entanglement
Juha-Pekka Pellonpää
Complete measurement of a quantum observable (POVM) is a measurement of the maximally refined version of the POVM. Complete measurements give information on multiplicities of measu…
Complete measurements of quantum observables
Juha-Pekka Pellonpää
We define a complete measurement of a quantum observable (POVM) as a measurement of the maximally refined version of the POVM. Complete measurements give information from the multi…
Completely positive maps on modules, instruments, extremality problems, and applications to physics
Juha-Pekka Pellonpää
Convex sets of completely positive maps and positive semidefinite kernels are considered in the most general context of modules over -algebras and a complete charaterization o…
Complete Characterization of Pure Quantum Measurements and Quantum Channels
Juha-Pekka Pellonpää
We give a complete characterization for pure quantum measurements, i.e., for POVMs which are extremals in the convex set of all POVMs. Such measurements are free from classical noi…
Extreme phase and rotated quadrature measurements
Juha-Pekka Pellonpää
We determine the extreme points of the convex set of covariant phase observables. Such extremals describe the best phase parameter measurements of laser light - the best in the sen…
The canonical phase measurement is pure
Teiko Heinosaari, Juha-Pekka Pellonpää
We show that the canonical phase measurement is pure in the sense that the corresponding positive operator valued measure (POVM) is extremal in the convex set of all POVMs. This me…
State reconstruction formulas for the s-distributions and quadratures
Jukka Kiukas, Juha-Pekka Pellonpää, Jussi Schultz
We consider the method of infinite matrix inversion in the context of quantum state reconstruction. Using this method we give rigorous proofs for reconstruction formulas for the Ca…
Extremal covariant positive operator valued measures: the case of a compact symmetry group
Claudio Carmeli, Teiko Heinosaari, Juha-Pekka Pellonpää +1
Given a unitary representation U of a compact group G and a transitive G-space , we characterize the extremal elements of the convex set of all U-covariant positive operator val…
Two questions on quantum statistics
Pekka Lahti, Juha-Pekka Pellonpaa, Kari Ylinen
The determination of a quantum observable from the first and second moments of its measurement outcome statistics is investigated. Operational conditions for the moments of a proba…
A dilemma in representing observables in quantum mechanics
D. A. Dubin, M. A. Hennings, P. Lahti +1
There are self-adjoint operators which determine both spectral and semispectral measures. These measures have very different commutativity and covariance properties. This fact pose…
The phase representation of covariant phase observables
Juha-Pekka Pellonpaa
Covariant phase observables are obtained by defining simple conditions for mappings from the set of phase wave functions (unit vectors of the Hardy space) to the set of phase proba…
On the structure of covariant phase observables
Juha-Pekka Pellonpaa
We study the mathematical structure of covariant phase observables. Such an observable can alternatively be expressed as a phase matrix, as a sequence of unit vectors, as a sequenc…
Are Number and Phase Complementary Observables?
Paul Busch, Pekka Lahti, Juha-Pekka Pellonpaa +1
We study various ways of characterising the quantum optical number and phase as complementary observables.