58 citations · 121 across the 8 of their papers we have counts for
8 papers
Nonlinear Qubit Transformations
Lucien Hardy, David D. Song
We generalise our previous results of universal linear manipulations [Phys. Rev. A63, 032304 (2001)] to investigate three types of nonlinear qubit transformations using measurement…
Duality and Decoherence Free Subspaces
David D. Song, Richard J. Szabo
Quantum error avoiding codes are constructed by exploiting a geometric interpretation of the algebra of measurements of an open quantum system. The notion of a generalized Dirac op…
Universal Manipulation of a Single Qubit
Lucien Hardy, David D. Song
We find the optimal universal way of manipulating a single qubit, |psi(theta,phi)>, such that (theta,phi)->(theta-k,phi-l). Such optimal transformations fall into two classes. For…
Entanglement Swapping Chains for General Pure States
Lucien Hardy, David D. Song
We consider entanglement swapping schemes with general (rather than maximally) entangled bipartite states of arbitary dimension shared pairwise between three or more parties in a c…
Quantum Anti-Cloning
David D. Song, Lucien Hardy
We derive the transformation for the optimal universal quantum anti-cloner which produces two anti-parallel outputs for a single input state. The fidelity is shown to be 2/3 which…
No Signalling and Probabilistic Quantum Cloning
Lucien Hardy, David D. Song
We show that the condition of no faster-than-light signalling restricts the number of quantum states that can be cloned in a given Hilbert space. This condition leads to the constr…