“The Necessary War: Canadians Fighting the Second World War 1939–1943, Volume One (Book Review)” by Tim Cook & “Fight to the Finish: Canadians in the Second World War 1944–1945, Volume Two (Book Review)” by Tim Cook

Review of The Necessary War: Canadians Fighting the Second World War 1939–1943, Volume One & Fight to the Finish: Canadians in the Second World War 1944–1945, Volume Two by Tim Cook

Review of Dominion of Race: Rethinking Canada’s International History by Laura Madokoro, Francine McKenzie and David Meren, eds.

Review of Dominion of Race: Rethinking Canada’s International History by Laura Madokoro, Francine McKenzie and David Meren, eds

Two Years Below the Horn: Operation Tabarin, Field Science, and Antarctic Sovereignty, 1944–1946 (Book Review) by Andrew Taylor, edited by Daniel Heidt and P. Whitney Lackenbauer

Review of Two Years Below the Horn: Operation Tabarin, Field Science, and Antarctic Sovereignty, 1944–1946 by Andrew Taylor, edited by Daniel Heidt and P. Whitney Lackenbauer

Towards feedback control of entanglement

We provide a model to investigate feedback control of entanglement. It consists of two distant (two-level) atoms which interact through a radiation field and becomes entangled. We then show the possibility to stabilize such entanglement against atomic decay by means of a feedback action.Comment: 6 pages, 4 figure

Optomechanical tailoring of quantum fluctuations

We propose the use of feedback mechanism to control the level of quantum noise in a radiation field emerging from a pendular Fabry-Perot cavity. It is based on the possibility to perform quantum nondemolition measurements by means of optomechanical coupling.Comment: ReVTeX file, 8 pages, 1 Postscript figure. to appear in J. Opt. B: Quant. Semiclass. Op

Quantum error correction for continuously detected errors

We show that quantum feedback control can be used as a quantum error correction process for errors induced by weak continuous measurement. In particular, when the error model is restricted to one, perfectly measured, error channel per physical qubit, quantum feedback can act to perfectly protect a stabilizer codespace. Using the stabilizer formalism we derive an explicit scheme, involving feedback and an additional constant Hamiltonian, to protect an ($n-1$)-qubit logical state encoded in $n$ physical qubits. This works for both Poisson (jump) and white-noise (diffusion) measurement processes. In addition, universal quantum computation is possible in this scheme. As an example, we show that detected-spontaneous emission error correction with a driving Hamiltonian can greatly reduce the amount of redundancy required to protect a state from that which has been previously postulated [e.g., Alber \emph{et al.}, Phys. Rev. Lett. 86, 4402 (2001)].Comment: 11 pages, 1 figure; minor correction

Entanglement under restricted operations: Analogy to mixed-state entanglement

We show that the classification of bi-partite pure entangled states when local quantum operations are restricted yields a structure that is analogous in many respects to that of mixed-state entanglement. Specifically, we develop this analogy by restricting operations through local superselection rules, and show that such exotic phenomena as bound entanglement and activation arise using pure states in this setting. This analogy aids in resolving several conceptual puzzles in the study of entanglement under restricted operations. In particular, we demonstrate that several types of quantum optical states that possess confusing entanglement properties are analogous to bound entangled states. Also, the classification of pure-state entanglement under restricted operations can be much simpler than for mixed-state entanglement. For instance, in the case of local Abelian superselection rules all questions concerning distillability can be resolved.Comment: 10 pages, 2 figures; published versio