General rules for bosonic bunching in multimode interferometers

We perform a comprehensive set of experiments that characterize bosonic bunching of up to 3 photons in interferometers of up to 16 modes. Our experiments verify two rules that govern bosonic bunching. The first rule, obtained recently in [1,2], predicts the average behavior of the bunching probability and is known as the bosonic birthday paradox. The second rule is new, and establishes a n!-factor quantum enhancement for the probability that all n bosons bunch in a single output mode, with respect to the case of distinguishable bosons. Besides its fundamental importance in phenomena such as Bose-Einstein condensation, bosonic bunching can be exploited in applications such as linear optical quantum computing and quantum-enhanced metrology.Comment: 6 pages, 4 figures, and supplementary material (4 pages, 1 figure

Fermonic anyons: entanglement and quantum computation from a resource-theoretic perspective

Often quantum computational models can be understood via the lens of resource theories, where a computational advantage is achieved by consuming specific forms of quantum resources and, conversely, resource-free computations are classically simulable. For example, circuits of nearest-neighbor matchgates can be mapped to free-fermion dynamics, which can be simulated classically. Supplementing these circuits with nonmatchgate operations or non-gaussian fermionic states, respectively, makes them quantum universal. Can we similarly identify quantum computational resources in the setting of more general quasi-particle statistics, such as that of fermionic anyons? In this work, we develop a resource-theoretic framework to define and investigate the separability of fermionic anyons. We build the notion of separability through a fractional Jordan-Wigner transformation, leading to a Schmidt decomposition for fermionic-anyon states. We show that this notion of fermionic-anyon separability, and the unitary operations that preserve it, can be mapped to the free resources of matchgate circuits. We also identify how entanglement between two qubits encoded in a dual-rail manner, as standard for matchgate circuits, corresponds to the notion of entanglement between fermionic anyons. Though this does not coincide with the usual definition of qubit entanglement, it provides new insight into the limited capabilities of matchgate circuits.Comment: 7+19 pages, 3 figure

Indirect tests of the Randall-Sundrum model

I present phenomenological implications of the Randall-Sundrum model for indirect searches, specifically a selection of flavor observables and Higgs-related collider searches. I review the interplay of constraints from CP violation in flavor physics, possible effects in rare decays, and model-specific protection mechanisms. Deviations in the Higgs couplings to fermions and, at one-loop, to gluons are unexpectedly strong and lead to strong modifications in Higgs searches.Comment: 8 pages, 6 figures; Talk given at Discrete '10: Symposium on Prospects in the Physics of Discrete Symmetries, Rome, Italy, 6-11 Dec 201

Some Myths on FedEx, Home Values

Whenever a new development is opposed by neighboring home owners, one of the opponents’ foremost claims is that the development will reduce residential property values. Sometimes the claims are borne out by the facts, sometimes not

What is the True State of U.S. Furniture Manufacturing?

American furniture manufacturing has taken it on the chin over the last decade. Manufacturing jobs have disappeared as more and more production has moved overseas. Manufacturers that used to have simple organizations now must manage complex global supply chains. And all but a few manufacturers have become manufacturer/importers

The Disappearing Dollar

The dollar is getting weaker. When compared to other currencies such as the euro and the British pound, it’s lost about a quarter of its value over the last two years. In spite of a few minor surges this month, analysts expect the dollar to continue its slide throughout the remainder of 2005. What are the implications of the weakening dollar? Should we care

A Drop in the Bucket: Oil from Arctic Refuge Won’t Yield Much Relief

What a difference a year makes! Last April I wrote a column that explained why gasoline prices had been rising for months. The reason was tight refining capacity in the U.S., combined with the complicated array of gasoline blends that refiners are required by law to produce. Industry experts predicted that prices would moderate within a few months, as summer blends gradually replaced winter blends. And that’s what happened