Research

I am interested in quantum control problems concerning continuous quantum measurements in the presence of feedback. I've also worked, in the past, on quantum information theory with applications to certain models of black holes.

Why does the act of measuring a quantum system disturb it? As far as the axioms of quantum mechanics go, quantum measurement stands out as the only irreversible and discontinuous process that quantum states undergo. This is not always the case, however, as some quantum measurements can be designed to disturb quantum states only very weakly. It has already been shown that a rapid succession of such weak measurements can decompose any general quantum measurement into a continuous stochastic process using a feedback loop. Can these loops be implemented experimentally? Some physical systems, such as superconducting qubits, cannot be measured directly and have slow read-out times. In these cases, the measurement can be performed via a stream of probes. Which general measurements can be performed this way?

Publications

Continuous decomposition of quantum measurements via Hamiltonian feedback

Jan Florjanczyk, Todd A. Brun
Journal: Phys. Rev. A 92, 062113
Preprint: arxiv:quant-ph/1504.03772

Continuous decomposition of quantum measurements via qubit-probe feedback

Jan Florjanczyk, Todd A. Brun
Journal: Phys. Rev. A 90, 032102
Preprint: arxiv:quant-ph/1406.4956

The locking-decoding frontier for generic dynamics

Frédéric Dupuis, Jan Florjanczyk, Patrick Hayden, Debbie Leung
Journal: rspa.2013.0289
Preprint: arxiv:quant-ph/1011.1612

Blog

Stratified Bayesian Blocks

Experience

Data Scientist Intern
ID Analytics, San Diego, CA, Summer 2015

Implemented the reusable holdout algorithm, used to avoid overfitting, as a python module
Developed a novel algorithm for smart histogram bins that yielded lift on existing decision tree models
Applied the above algorithm to a test dataset using Apache Spark, Apache Parquet, and Python numpy

Research Assistant & Teaching Assistant, Annenberg fellow
University of Southern California, Viterbi School of Engineering, Los Angeles, CA, 2011 - Present

Develop and prove theoretical results addressing open problems quantum control theory
Model quantum dynamical systems using numerical simulations
Present results as talks and posters and contribute to grant applications
Teach discussion sections and grade tests and assignments for Applied Linear Algebra and Probability and Statistics

Research Assistant
Atomic Energy Canada Ltd., Deep River, ON, 2006 - 2007

Prototyped a computer vision-based tool to inspect surfaces in CANDU nuclear reactor fuel channels
Developed control and analysis software in LabView

Executive Organizer
TEDxMcGill, Montreal, QC, 2010 - 2011

Doubled the number of attendees over the previous year
Curated and prepared student, academic, and professional speakers for the event
Secured financial sponsors as part of $30,000 event budget

Education

University of Southern California

PhD. Electrical Engineering, 2016
Advisor: Todd A. Brun
Research topics: quantum control, quantum error correction, quantum differential privacy

McGill University

M.Sc. Computer Science, 2011
Advisor: Patrick Hayden
Thesis: The locking-decoding frontier for generic dynamics

McGill University

B.Sc. Joint Honours in Mathematics and Physics, 2009

Skills

Research

quantum information theory and control theory, matrix analysis, stochastic processes and differential equations

Programming

Python, MATLAB, numerical simulations, R

Data science

Python with pandas, numpy, scikit-learn, matplotlib, Apache Spark and Parquet, git, unix shell

Web development

MVC patterns, CSS frameworks (bootstrap and foundation), Jade, SCSS, Coffeescript, AngularJS, Flask, templating,

Projects

Stratified Bayesian Blocks
Smart histogram bins for mixed discrete/continuous data, based on Scargle and Jake VDP's Bayesian Blocks

python
numpy
data science
algorithms

Symplectic.jl
Symplectic matrices for stabilizer quantum codes in Julia

Julia
quantum

HermAlgLab
A collection of functions to test the behaviour of matrix algebras built up from Hermitian matrices.

quantum
algebra
MATLAB

PyPsych
Data-crunching automation for psychology experiments (SMI BeGaze, Biopac,...)

python
pandas
data science
physio

CameraPlaysEmulator
A Python app that captures input from a webcam, sends commands to a video game emulator, and streams to Twitch.tv.

python
openCV

Flaskenberg
App for crowd-sourcing the annotation of datasets. Consists of a Python Flask restful API and an AngularJS front-end.

python
flask
javascript
angularJS
mvc

BeauSia.com
Site design and wordpress theme development

php
jade
scss
gulp
boostrap

Teleporter Productions
Static site design using responsive layout

photoshop
jade
scss
node
gulp

Teleporter Booklet
Investment packet document design in Adobe InDesign

InDesign
print
design

Ewa Taryma-Myslinski
Site design and Ruby on Rails development to implement fast and easily updatable artwork gallery

ruby
rails
scss
design

TEDxUSC Schedule
Document design in Adobe InDesign for the technical lead-up to TEDxUSC

InDesign
event planning