Infinity – the mathematical notion of no limits. Our physical world has many limits. Yet mathematically infinity is reality.
A classical current in a conductor radiates a classical electromagnetic field. We explore some properties of the field radiated by a conductor when electron transport must be described by quantum mechanics, i.e. when the electron current becomes quantum itself.
The behavior of conventional transistors derives from large numbers of acceptor and donor impurities that promote carriers into the valence and conduction bands. More recently, nano-electronic devices based on the bound states of individual dopant impurities in silicon have received considerable attention for quantum computation, due to the long spin coherence times of dopants in silicon. This invariably requires control over dopant wavefunctions and the interactions between individual dopants [1].
David Luong of the Department of Physics and Astronomy will be defending his thesis:
The Practical Realization of Quantum Repeaters: An Exploration
David is supervised by Professor Norbert Lütkenhaus.
We report a quantum hacking strategy on a Continuous-Variable (CV) Quantum Key Distribution (QKD) system by inserting an external light. In the implementations of CV QKD systems, transmitting openly local oscillator pulses is a potential vulnerability for an eavesdropper to launch side channel attacks. In this work, other than targeting on local oscillator, we concern two imperfections in a balanced homodyne detector used in CV QKD system: the imbalance in the beam splitter and the finite linear detection limit.
In this talk, I will discuss correlations that can be generated by performing local measurements on bipartite quantum systems. I'll present an algebraic characterization of the set of quantum correlations which allows us to identify an easy-to-compute lower bound on the smallest Hilbert space dimension needed to generate a quantum correlation. I will then discuss some examples showing the tightness of our lower bound.
Juan Miguel Arrazola of the Department of Physics and Astronomy will be defending his thesis:
Practical Quantum Communication
Juan Miguel is supervised by Professor Norbert Lütkenhaus.
In recent years, Bayesian methods have been proposed as a solution to a wide range of issues in quantum state and process tomography. In this talk, we make these methods practical by solving three distinct problems: numerical intractability, a lack of informative prior distributions, and an inability to track time-dependent processes. Our approach allows for practical computation of point and region estimators for quantum states and channels, and allows tracking of time-dependent states.
Anirudh of the Department of Physics and Astronomy will be defending his thesis:
Experimentally Testable Noncontextuality Inequalities via Fourier-Motzkin Elimination.
Jihyun is supervised by Professors Joseph Emerson and Robert Spekkens.