PhD student
Department of Physics & Astronomy and Institute for Quantum Computing
Back by popular demand, CryptoWorks21 will once again launch the Intellectual Property (IP) Management Lunch and Learn Lecture Series! Our knowledgeable speakers will provide more in-depth presentation built from the previous sessions.
The lectures are designed for researchers working in areas related to information technology, including cryptography and quantum technology.
As we approach the development of a quantum computer with tens of
well-controlled qubits, it is natural to ask what can be done with
such a device. Specifically, we would like to construct an example of
a practical problem that is beyond the reach of classical computers,
but that requires the fewest possible resources to solve on a quantum
computer. We address this problem by considering quantum simulation of
spin systems, a task that could be applied to understand phenomena in
The toric code is a topological quantum error correcting code, and an example of a stabilizer code, defined on a two-dimensional spin lattice. It also represents the simplest example of topological order -- Z2 topological order that was first studied in the context of Z2 spin liquid. I will talk about our recent progress in the search for a toric code topological order in the kagome antiferromagnetic spin system.
There are tremendous efforts underway to better understand systems with topological order --- global properties that are not discernible locally. The best-known examples are quantum Hall effects in electronic systems, where insensitivity to local properties manifests itself as conductance through edge states which are insensitive to defects and disorder.
I will report on dynamical magnetic susceptibility measurements of
both bulk and thin film samples of the spin glass Copper Manganese.
By studying the Thermoremanent Magnetization (TRM) of multi-layer thin
films of various thicknesses, we are able to show the maximum energy
barrier encountered during correlated spin flip transitions is cut off
by the thickness of the film and is independent of temperature. The
distribution of energy barriers is shown to follow from a hierarchical
I will present a realization of a great photon pair source based on parametric down-conversion, and discuss a not-so-great limit to the performance of photon pair sources in general. The former is a fully fiber-coupled waveguide pair source with 46% raw heralding efficiency, and no optical alignment required. The latter restricts the achievable heralding efficiency, when spectrally filtering the photons to increase the purity.
As we know, spacetime is not flat at the cosmological scale. In order to describe spacetime, in General Relativity theory (GR), we need a continuous and differentiable manifold and a formal way to account for the continuous distortion of the metrics. The main point is that changing coordinate systems should not affect physics laws (General Covariance). However at the Planck length, matter is not continuous and obeys Quantum Theory (QT).
Recent rapid advancements in nanofabrication technologies have widened the realm of possibilities in nanophotonics, nonlinear and sub-wavelength optics. Realizing nonlinear optics in subwavelength scale paves the way for low cost integrated photonics. Ultra-high-Q photonic crystal nanocavities and nanostructured materials are examples of such structures. Those structures offer very small mode volume guaranteeing highly enhanced field intensity.