400 citations · 2.5k across the 79 of their papers we have counts for
6 papers · 2 filters
Off-diagonal mixed state phases in unitary evolution
Erik Sjöqvist, Stefan Filipp
Off-diagonal mixed state phases based upon a concept of orthogonality adapted to unitary evolution and a proper normalisation condition are introduced. Some particular instances ar…
Precession and interference in the Aharonov-Casher and scalar Aharonov-Bohm effect
Philipp Hyllus, Erik Sjöqvist
The ideal scalar Aharonov-Bohm (SAB) and Aharonov-Casher (AC) effect involve a magnetic dipole pointing in a certain fixed direction: along a purely time dependent magnetic field i…
Off-diagonal geometric phase for mixed states
Stefan Filipp, Erik Sjöqvist
We extend the off-diagonal geometric phase [Phys. Rev. Lett. {\bf 85}, 3067 (2000)] to mixed quantal states. The nodal structure of this phase in the qubit (two-level) case is comp…
Quantum computation using the Aharonov-Casher set up
Marie Ericsson, Erik Sjöqvist
It is argued that the Aharonov-Casher set up could be used as the basic building block for quantum computation. We demonstrate explicitly in this scenario one- and two-qubit phase…
Generalization of geometric phase to completely positive maps
Marie Ericsson, Erik Sjöqvist, Johan Brännlund +2
We generalize the notion of relative phase to completely positive maps with known unitary representation, based on interferometry. Parallel transport conditions that define the geo…
Mixed state geometric phases, entangled systems, and local unitary transformations
Marie Ericsson, Arun K. Pati, Erik Sjöqvist +2
The geometric phase for a pure quantal state undergoing an arbitrary evolution is a ``memory'' of the geometry of the path in the projective Hilbert space of the system. We find th…