Tomer Shacham

Entanglement Swapping between Photons that have Never Coexisted

The role of the timing and order of quantum measurements is not just a fundamental question of quantum mechanics, but also a puzzling one. Any part of a quantum system that has finished evolving can be measured immediately or saved for later, without affecting the final results, regardless of the continued evolution of the rest of the system. In addition, the nonlocality of quantum mechanics, as manifested by entanglement, does not apply only to particles with spacelike separation, but also to particles with timelike separation. In order to demonstrate these principles, we generated and fully characterized an entangled pair of photons that have never coexisted. Using entanglement swapping between two temporally separated photon pairs, we entangle one photon from the first pair with another photon from the second pair. The first photon was detected even before the other was created. The observed two-photon state demonstrates that entanglement can be shared between timelike separated quantum systems.

A light stop with flavor in natural SUSY

A bstractThe discovery of a SM-like Higgs boson near 125 GeV and the flavor texture of the Standard Model motivate the investigation of supersymmetric quiver-like BSM extensions. We study the properties of such a minimal class of models which deals naturally with the SM parameters. Considering experimental bounds as well as constraints from flavor physics and Electro-Weak Precision Data, we find the following. In a self-contained minimal model — including the full dynamics of the Higgs sector — top squarks below a TeV are in tension with b → sγ constraints. Relaxing the assumption concerning the mass generation of the heavy Higgses, we find that a stop not far from half a TeV is allowed. The models have some unique properties, e.g. an enhancement of the h →

Projection of two biphoton qutrits onto a maximally entangled state

b\overline{b}

Resource efficient source of multiphoton polarization entanglement.

,

On the spectrum of direct gaugino mediation

\tau \overline{\tau}

ON CONTINUUM-DRIVEN WINDS FROM ROTATING STARS

decays relative to the h → γγ one, a gluino about 3 times heavier than the stop, an inverted hierarchy of about 3 ÷ 20 between the squarks of the first two generations and the stop, relatively light Higgsino neutralino or stau NLSP, as well as heavy Higgses and a W′ which may be within reach of the LHC.

A non-renormalization theorem in gapped quantum field theory

We propose and demonstrate the projection of two quantum three state systems (qutrits) onto a maximally entangled state. The qutrits are represented by the polarization of biphotons — pairs of indistinguishable photons.

On the vacuum structure of the 3-2 model

Current photon entangling schemes require resources that grow with the photon number. We present a new approach that generates quantum entanglement between many photons, using only a single source of entangled photon pairs. The different spatial modes, one for each photon as required by other schemes, are replaced by different time slots of only two spatial modes. States of any number of photons are generated with the same setup, solving the scalability problem caused by the previous need for extra resources. Consequently, entangled photon states of larger numbers than before are practically realizable.

Projection of Two Biphoton Qutrits onto a Maximally Entangled State

In direct gauge mediation, the gaugino masses are anomalously small, giving rise to a split SUSY spectrum. Here we investigate the superpartner spectrum in a minimal version of “direct gaugino mediation”. We find that the sfermion masses are comparable to those of the gauginos — even in the hybrid gaugino-gauge mediation regime — if the messenger scale is sufficiently small.

Entanglement between photons that never co-existed

We study the dynamics of continuum-driven winds from rotating stars and develop an approximate analytical model. We then discuss the evolution of stellar angular momentum, and show that just above the Eddington limit, the winds are sufficiently concentrated toward the poles to spin-up the star. A twin-lobe structure of the ejected nebula is seen to be a generic consequence of critical rotation. We find that if the pressure in such stars is sufficiently dominated by radiation, an equatorial ejection of mass will occur during eruptions. These results are then applied to ?-Carinae. We show that if it began its life with a high enough angular momentum, the present-day wind could have driven the star toward critical rotation, if it is the dominant mode of mass loss. We find that the shape and size of the Homunculus nebula, as given by our model, agree with recent observations. Moreover, the contraction expected due to the sudden increase in luminosity at the onset of the Great Eruption explains the equatorial skirt as well.