Stefan's Blog

Teaching and Outreach

SpinWearables science through art educational kit: A small, colorful, programmable, wearable kit to facilitate student exploration of physics, engineering, and computer science.
Optics and Quantum Electronics Seminar: A seminar series at MIT hosting some of the best researchers in the field. I joined the organizing committee in 2020, expanding the seminar into publicly accessible online series
Quantum Huddle Seminar: Organized seminar to bring scientists together from fields that are seemingly unrelated but are dedicated to the goals of controlling and exploiting quantum systems. Establishing contact between these fields and spark a discussion about topics that we know from our respective perspectives but now introduced in an interdisciplinary light. Summer 2020.
Weekly Physics Olympiad Lectures: I lead weekly online lectures for preparation for the International Physics Olympiad. Anyone is welcome to join. The lectures are in Bulgarian. Ongoing since 2020.
Yale Prize Teaching Fellowship: For my work as a TA for MENG 404 "Medical Devices Design and Innovation" I was awarded the Prize Teaching Fellowship for 2016-2017. "The Prize Teaching Fellowships recognize outstanding performance and promise as a teacher. They are considered among the most important honors that Yale bestows upon graduate students."
Engineering Day for School Children: Under the umbrella of SWE I design and coordinate outreach activities in engineering, robotics, and electronics at Yale. I received the Yale Graduate School of Arts and Sciences Public Service award for this work. From 2016 to 2020.
GSI: I was the 2016-2017 coordinator for GSI, a large half-day science outreach event held 4 times a year at the Yale Physics Department.
in Bulgarian - Висше във Франция: Често полувачам въпроси относно висшето образование във Франция от български гимназисти които желаят да кандидатстват там. На тази страницa описвам моите преживявания във френската образователна система около 2010.

Research Highlights

Research Profile: My work at MIT and previous at Yale's Quantum Institute centers around characterization and control of quantum hardware, with projects on quantum circuit design, error correction, optimal control, and parameter estimation, with generous use of machine learning techniques. The sidebar has links to profile pages listing my published work: Google Scholar and ORCiD
Conference Posters and Presentations: A repository for talks that I have given.
Room-temperature Photonic Quantum Logic: Non-linear optics provides for a room-temperature realization of quantum computing as long as you can find a way to deal with the severely limited control Hamiltonians available in such hardware.
Optimized Entanglements Purification Circuits: Algorithms for optimization of quantum entanglement purification circuits and a repository of well performing circuits. Including extensions dealing with more general forms of entanglement.
Neural Network Decoder for Quantum Error Correcting Codes: A decoder with very high threshold for arbitrary stablizer codes (tested on the toric code). All of the software is available.
Visualizations of quantum gates and channels: Visualizations of holonomic quantum computing on cat-codes in harmonic oscillators, based on related PRL publication. Visualizations of the binary decision tree traversed during the feed-forward construction of a quantum channel, based on related PRB publication.

Open Source

Github Profile: My Github profile lists open source software I have created or worked on, including research projects and small one-off tools.
QuantumClifford.jl: A Julia package for working with quantum stabilizer states and Clifford circuits that act on them. The package is already very fast for the majority of common operations. The package has some original implementations of methods for the simulation of noisy Clifford circuits: a standard Monte Carlo approach, but also a symbolic perturbative expansion methods for simulating noise.
Quantikz.jl: A minimal Julia package for drawing quantum circuits using the quantikz and tikz TeX libraries.
SymPy: Sympy is a Computer Algebra library on which I have worked as a volunteer during most of my undergrad. See the SymPy tag. The Diff Geom in Python Page describes work I did under a student scholarship from Google (GSoC).
Hamiltonian Engineering - BBQ formalism: A constraint solver for the design of Hamiltonians ("pumps") in the BBQ formalism from 2016.
Cutiepy: A small package from 2015 for numerical simulation of quantum systems. Created as an alternative to `qutip` due to code generation limitations in the latter. It was an amusing experiment in code generation, but now Tensorflow and Theano support complex sparse matrices, so you can just use them with a bit of a wrapper. Or QuantumOptics.jl in Julia.
Genealogy Software: Web based collaborative software for family tree research.
Bulgarian Parliament Tracker: The first public tracker and visualizer of parliamentary votes in the Bulgarian parliament, originally at parlamentaren-kontrol.com. Supplanted in 2014 by the obshtestvo.bg community. The scraper and visualization code are available on github.