Michelle M Victora

• Doctor of Philosophy
• University of Illinois Urbana-Champaign

We present an approach to entanglement purification on complex quantum network architectures, that is, how a quantum network built from repeaters with limited processing fidelity can purify and distribute entanglement between users. In particular, we explore how noisy gates, depolarizing channels, and finite memory storage time influence the perfor...

Photonic quantum memories will play an essential role in synchronizing nodes of quantum networks. Here we present a system that can store polarization and time-bin qubits for up to 12.5 µ s over a THz bandwidth.

Quantum optical memories are a key component of quantum information applications. Here we develop a system with multiplexed free-space storage cavities, able to efficiently store single photons for up to 12.5 µs over several nanometers of bandwidth.

We present an approach to purification and entanglement routing on complex quantum network architectures, that is, how a quantum network equipped with imperfect channel fidelities and limited memory storage time can distribute entanglement between users. We explore how network parameters influence the performance of path-finding algorithms necessar...

Quantum information processing with photons can be greatly enhanced by incorporating time-multiplexing methods. Not only can time-bin encoding be very useful in its own right, multiplexing techniques can lead to more efficient single- and multi-photon sources, improved detectors, and high-bandwidth quantum memories, as well as enhanced applications...

The human eye contains millions of rod photoreceptor cells, and each one is a single-photon detector. Whether people can actually see a single photon, which requires the rod signal to propagate through the rest of the noisy visual system and be perceived in the brain, has been the subject of research for nearly 100 years. Early experiments hinted t...

Temporal summation is an important feature of the visual system which combines visual signals that arrive at different times. Previous research estimated complete summation to last for 100 ms for stimuli judged "just detectable." We measured the full range of temporal summation for much weaker stimuli using a new paradigm and a novel light source,...

Changes in the core intrinsic toroidal rotation velocity following L- to H- and L- to I-mode transitions have been investigated in Alcator C-Mod tokamak plasmas. The magnitude of the co-current rotation increments is found to increase with the pedestal temperature gradient and q95, and to decrease with toroidal magnetic field. These results are cap...

We discuss techniques using a heralded single-photon source to study the lower limit of human vision, specifically measuring temporal integration using multi-photon trials, and report preliminary results at the few-photon level.

Using a spatially-resolving x-ray spectrometer system, the toroidal rotation velocity in Alcator C-Mod plasmas is measured and analyzed. At the L-H and L-I transition, there is a co-current movement in the toroidal rotation velocity.The propagation of this rotational velocity from the edge to the core of the torus was measured following the L- to H...

X-ray spectra of n = 2 to 1 transitions in hydrogen-like Ca19 +, helium-like Ca18 + and nearby satellites have been obtained from Alcator C-Mod tokamak plasmas using a spatially imaging high resolution x-ray spectrometer system. For Ca19 +, the intensity ratio of Ly?2 (1s 1S1/2?2p 2P1/2) to Ly?1 (1s 1S1/2?2p 2P3/2) was found to be ~0.531 ? 0.005 ov...

The excitation of a heavy particle mode [1,2] at the plasma edge is considered as the signature of the I-Regime [3]. The mode phase velocity, predicted in the electron diamagnetic velocity direction, was confirmed by the experiments [4]. The outward impurity transport produced by this mode is consistent with the observation that impurities accumula...