Farid Ghobadi

(Mar. 4, `14)


       I describe a scheme for creating and detecting opto-mechanical entanglement by storing one component of an entangled state of light in a mechanical resonator and then retreiving it. Using     micro-macro entanglement of light as recently demonstrated experimentally, one can then create     opto-mechanical entangled states where the components of the superposition are                         macroscopically different.

Narges Khalaji

(May 21, `13)

 

The Shannon/Nyquist sampling theorem specifies that to avoid losing information when capturing a signal, one must sample at least two times faster than the signal bandwidth. In many applications the Nyquist rate is so high, and in other applications, increasing the sampling rate is very expensive. Compressive Sensing (CS) is a method to capture and represent compressible signals at a rate significantly below the Nyquist rate. We only need to collect a small number of data, and then use CS to reconstruct the signal. This method employs nonadaptive linear projections that preserve the structure of the signal; the signal is then reconstruct from these projections using an optimization process.

 

Hamed Saberi

(Apr. 30, `13)

  

I will demonstrate throughout this talk how the powerful tensor network formalism of quantum information can be employed for the identification of the entanglement classes of /N/ qubits under stochastic local operations and classical communication (SLOCC), and without resourcing to any entanglement measure. While reproducing the former inductive classification of Lamata /et a/l [Phys. Rev. A *74*, 052336 (2006) ] for the bipartite and tripartite cases, the approach provides vivid insights into the bipartite components of a given mutipartite entangled state and promises at the same time straightforward and systematic generalization to higher parties beyond the reach of all /hitherto /known analytical approaches to the classification of multipartite entanglement under SLOCC.

Abolfazl Bayat

(Dec. 27, `11)

  

 

In this talk, I will discuss how strongly correlated many-body systems may realize a number of quantum information and computation tasks. I also review recent experimental progress of cold atoms in optical lattices to implement our theoretical achievements. In fact, this is a reverse engineering approach to take the experimental achievements for developing further theoretical ideas which are immediately realizable in experiments.

Peyman Ahmadi

(Jan. 3, `12)

  

In what forms does matter organize itself under the influence of interaction? This is the fundamental question of many-body physics, which arises at all length scales: from the dense quark matter present in the beginning of our Universe, to the atomic nucleus, the electrons inside a metal, and the inner workings of a neutron star. While strong interactions between particles do not allow for a simple description of such systems, samples of ultracold gases act as a "magnifying glass" in the study of physics of strongly correlated matter. Unlike condensed matter systems, many-body processes can be probed in real time, in or out of equilibrium in dilute mixtures of ultracold gases. This line of research has great potential to shed light on mechanisms responsible for High-Tc superconductivity and quantum magnetism, by providing a fully controllable environment in which fundamental models of condensed matter physics can be tested with the precision of atomic physics.

To realize such a system, we have constructed a new apparatus that allows cooling four different species of atoms, fermionic 6Li and 40K, and bosonic 23Na and 41K. Using this system, we have realized a Bose Einstein condensate of 41K immersed in a Fermi sea of 40K and detected a wide Feshbach resonance between them. A lifetime exceeding several tens of milliseconds is measured at resonance for this mixture. Currently, we use this mixture to study many-body effects on the physics of impurity atom interacting with its environment. In this talk, I will summarize our observations and the progress we have made towards understanding the science of impurity physics.