Stefan Krastanov

Assistant Professor at UMass Amherst

Research Experience


Assistant Professor

UMass Amherst's College of Information & Computer Science Amherst, Massachusetts
Starting a group focused on modeling, control, and optimization of quantum computational and networking hardware.

Research Scientist

MIT's Research Laboratory of Electronics Cambridge, Massachusetts
Continuing work in Dirk Englund's group at MIT, leading a number of subprojects and supervising multiple graduate and undergraduate students: quantum control and protocol design for hybrid optical-acoustic-spin hardware, unitary optical neural network hardware, large scale quantum hardware simulation and verification software, and novel classically-efficient entanglement purification methods.

Postdoctoral Scholar

MIT's Research Laboratory of Electronics
Harvard's School of Engineering and Applied Sciences
Cambridge, Massachusetts
Member of Dirk Englund's group at MIT and Prineha Narang's group at Harvard. Work on photonic architectures for quantum computing with potential for room temperature realizations as well as more general noise mitigation in quantum hardware. Dealing with problems of control, error correction, networking, and algorithm design. Main publications below (see last page for complete list).
  • Optically Heralded Entanglement of Superconducting Systems in Quantum Networks, PRL, 2021 a new heralded networking protocol for superconducting transmon devices with unprecedented fidelity compared to typical transduction approaches, applicable to present-day transduction hardware.
  • Heterogeneous multipartite entanglement purification for size-constrained quantum devices, PRR, 2021 optimized purification circuits for multi-qubit entangled states, significantly outperforming previous protocols.
  • Quantum Coding with Low-Depth Random Circuits, PRX, 2021 a study of quantum error correction codes generated by random (local) circuits.
  • Room-Temperature Photonic Logical Qubits via Second-Order Nonlinearities, Nature Communications, 2021 a paradigm for room-temperature photonic quantum logic that significantly simplifies the realization of various quantum circuits, and in particular, of error correction.

Research Assistant, Graduate Student

Yale Quantum Institute New Haven, Connecticut
Member of Prof. Liang Jiang's group. Work on quantum computing and communication, optimal control, parameter estimation, quantum circuit design, error correction. Main publications below (see last page for complete list).
  • Stochastic Estimation of Dynamical Variables, QST, 2019 A stochastic algorithm for the estimation/calibration of Hamiltonians and Lindbladians. Saturates information theory bounds and is resistant to state preparation and measurement errors.
  • Optimized Entanglement Purification, Quantum, 2019 Quantum entanglement purification circuits designed by a genetic algorithm, outperforming known circuits in the regime of noisy intermediate scale devices.
  • Deep Neural Network Probabilistic Decoder for Stabilizer Codes, Scientific Reports, 2017 A general decoder for small stabilizer codes. First neural net decoder architectures decoding the full stabilizer.
  • Universal control of an oscillator with dispersive coupling to a qubit, PRA, 2015 One of the first constructions for efficient and complete unitary control of a transmon/cavity system.

Undergrad Research Projects

Internships and Class Projects Lyon, France
Worked on a symbolic differential geometry module for the Computer Algebra System “SymPy” under the Google Summer of Code: work based on “Functional Differential Geometry” by Wisdom and Sussman, MIT. Other computational work includes Feynman diagrams generator inspired by MadGraph, and work on simulations in cosmology, astrophysics, and molecular dynamics. Experimental projects include Stimulated Brillouin Scattering work in metastable solid Helium during an internship at Laboratoire Kastler Brossel.



PhD, Physics

Yale Quantum Institute, Yale University New Haven, Connecticut
Quantum Computing Research, under Prof. Liang Jiang. PhD dissertation defended and submitted. Degree to be awarded in December 2019.

Integrated Bachelor and Master of Science, Physics and Chemistry

Ecole Normale Supérieure de Lyon Lyon, France
  • Autumn 2012 Student exchange at ETH Zürich for one semester as a Master student.
  • 2010 - 2013 Integrated Bachelor and Master of Science, Ecole Normale Supérieure de Lyon with the status of a normalien. The ENS Lyon is a highly selective Grande école. Entrance is granted by competitive exams. It trains researchers and teachers in the sciences and the humanities. It's also an active research center.
  • 2010 Grandes Écoles competitive exam Admitted at Ecole Polytechnique, Paris and Ecole Normale Supérieure de Lyon.
  • 2008 - 2010 Diplôme CPGE, Lycée Louis le Grand, Paris. The Classes Préparatoires aux Grandes Écoles (CPGE) are two very selective years acting as a prep course with the main goal of training students for enrollment in one of the Grandes écoles. The workload is generally very high with focus on Mathematics, Physics and Chemistry. The Grandes écoles are higher education establishments outside the main framework of the French university system. They include science & engineering schools and the three écoles normales supérieures. Due to their competitive entrance exams, they are widely regarded as a prestigious curriculum by students, and traditionally have produced most of France's scientists and executives.

Open Source Software Projects



One of the fastests and most versatile software tools for working with Clifford Quantum Circuits through the tableaux method.


Drawing quantum circuits in the Julia language (based on the quantikz latex package).

Simulator and optimizer (through genetic algorithms) of realistically noisy entanglement purification circuits.

SymPy's differential geometry module

I am the author of the differential geometry module for the SymPy computer algebra system. I also authored SymPy's plotting module.

Teaching Experience



MIT EECS Cambridge, Massachusetts
One of the lecturers for the introductory course on Machine Learning at MIT, also responsible for the e-learning infrastructure (more than 600 students with heavy use of online tools).

International Physics Olympiad Prep

Leading weekly high school classes in preparation for Physics Olympiads.

Teaching Fellow and Outreach Lead

Yale University New Haven, Connecticut
  • Project Based Interdisciplinary Classes In project based learning one teaches the students that they have the skills to actively make the world a better place. I have been a teaching fellow and a consultant for numerous classes that have run at Yale's Center for Engineering Innovation & Design (Yale's academic hacker space), guiding students in redesigning the network of exhibits in one of the Smithsonian museums on the National Mall in Washington; creating sensor networks for smart homes; designing numerous medical devices in collaboration with Yale's Med School; building interactive art and museum installations.
  • Traditional Courses and Tutoring Intro Physics, lab and theory; Advanced Physics and Math; Senior level Engineering, Mechatronics; Some Computer Science.

Google Summer of Code Mentor

Sympy, Symbolic Computer Algebra Project (remote)
Mentor for two consecutive years at the 2013 and 2014 “Google Summer of Code” programs for the computer algebra system project SymPy.

Undergrad and High School Teaching experience

Volunteer in summer schools or Physics competition preparation Bulgaria and France
  • Authored for three consecutive years the problems for the Annual Physics Competitions of the Minu Balkanski Foundation and graded the submissions.
  • Tutored intensive summer courses for high school physics international competitions at the summer school of Theodisius Teodosiev and at High School of Mathematics and Natural Sciences “acad. N. Obreshkov”, Burgas, Bulgaria.
  • Mentor at the Google Code-In high school program for the computer algebra system project SymPy.
  • As a high school senior, tutored extracurricular Physics to underclassmen in preparation for Physics competitions.

STEM Outreach


Optics and Quantum Electronics Seminar Series

MIT Cambridge, Massachusetts
Joined the organizing committee in 2020, expanding the established RLE's seminar into publicly accessible online series. Created the entirety of the virtual infrastructure for these seminars, now publically available at

Quantum Huddle Summer Seminar Series

Harvard Earth, Virtual
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.

The SpinWheel wearable electronic jewelry for STEM education

Yale gradSWE New Haven, Connecticut
A lead designer behind the SpinWheel device, meant to teach Physics and Computer Science through a beautiful programmable wearable trinket. See

Engineering Day Coordinator

Yale gradSWE New Haven, Connecticut
Design and coordinate outreach activities in mathematical art, physics, engineering, robotics, and electronics for thousands of K12 students. History and current status of the project at

Girls Science Investigations Coordinator

Yale Physics Department New Haven, Connecticut
Coordinator for GSI, a 200-attendee half-day science outreach event held 4 times a year at the Yale Physics Department.

Awards and Fellowships


Graduate School Public Service Award for Disciplinary Outreach

Graduate School of Arts and Sciences, Yale University New Haven, Connecticut
For my work designing hands-on outreach events. The award recognizes a graduate school student who uses specific knowledge of his/her own discipline as the basis for voluntary service in the local community. Making knowledge and skills from one’s discipline relevant and useful to those in need in the community is the hallmark of this award.

Prize Teaching Fellowship

Graduate School of Arts and Sciences, Yale University New Haven, Connecticut
For my work as a teaching fellow for ENG404 "Medical Devices Design and Innovation" under the instruction of Dr. Joseph Zinter. 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.

Normalien Fellowship

Ecole Normale Supérieure de Lyon Lyon, France
Fellowship granted by the Ecole Normale Supérieures on the basis of their competitive entrance exam.

International Physics Olympiad Medals

Hanoi, Vietnam and Isfahan, Iran
Bronze and Silver medals at the 38th and 39th International Physics Olympiads.

Select Hobby Projects


YQI Art Installation on Non-contextual Hidden Variable Theories

Yale Quantum Institute New Haven, Connecticut
Under the instructions of Martha Lewis, YQI's artist in residence, I contributed much of the electronics behind the "I will be your qubit" art installation for New Haven's Arts and Ideas festival.

Motion-responsive Jewelry

Engineering Day outreach New Haven, Connecticut
In collaboration with colleagues in the School of Engineering, I have prototyped programmable earrings, sensing the motion of the wearer and encoding it in a whimsical pattern of lights.

Laser-projector Music Box

New Haven, Connecticut
A persistence of vision laser projector music box, with handcrafted galvanic mirrors, computer vision calibration, and custom vector-to-waveform control software.

Invited Talks and Lectures


  • Digital Twins for Quantum Hardware: Multi-formalism and Mixed-signal
    Quantum Networks MeetingBrookhaven National Lab
  • All-Photonic Artificial Neural Network Processor Via Non-linear Optics
    NTT-NSF meetingNTT
  • Digital Twins for Quantum Hardware: Multi-formalism and Mixed-signal
    PME Quantum Seminar SeriesUniversity of Chicago
  • Noisy Entanglement (on Color Centers)
    Internal WorkshopQuantum Network Technologies
  • Heralded Microwave Entanglement
    Internal WorkshopBBN Raytheon

  • The many layers of control and parameterization: from closed-form solutions to machine learning
    Quantum Control WorkshopUniversity of Arizona
  • Optimized Entanglement Purification
    The New York Quantum Computing MeetupNew York

  • Unboxing Quantum Black Box Models from Unitary to Non-Markovian Dynamics
    Internal SeminarAlibaba Quantum Lab
  • Optimized Entanglement Distilation
    NSF Workshop on Midscale Infrastructure for Quantum Photonic Science, Engineering and Technology
  • Stochastic Parameter Estimation in QIS (Canceled)
    Workshop on Scalable Information Processing with Quantum Nano-Photonics (SIPQNP)
  • Quantum Hardware Calibration and the STEADY Method
    Theoretical Physics Seminar SeriesUniversity of Massachusetts, Lowell

  • Quantum Error Correction for Engineers
    Internal Talks Aliro Quantum, Massachusetts
  • Stochastic Calibration of Quantum Hardware and Optimization of Circuits
    MIT Optics and Quantum Electronics SeminarMassachusetts Institute of Technology
  • Stochastic Estimator of Dynamical Variables
    Machine Learning for Quantum Technology WorkshopMax Planck Institute for the Science of Light, Erlangen, Germany

Publications (peer reviewed)


Quantum coding with low-depth random circuits

Physical Review X 11 (3), 031066
MJ Gullans, S Krastanov, DA Huse, L Jiang, ST Flammia
2021 First Author

Heterogeneous multipartite entanglement purification for size-constrained quantum devices

Physical Review Research 3 (3), 033164
S Krastanov, AS de la Cerda, P Narang
2021 First Author

Optically Heralded Entanglement of Superconducting Systems in Quantum Networks

Physical Review Letters 127 (4), 040503
S Krastanov, H Raniwala, J Holzgrafe, K Jacobs, M Lončar, MJ Reagor, DR Englund

Capturing non-Markovian dynamics on near-term quantum computers

Physical Review Research 3 (1), 013182
K Head-Marsden, S Krastanov, DA Mazziotti, P Narang
2021 First Author

Room-temperature photonic logical qubits via second-order nonlinearities

Nature communications 12 (1), 1-10
S Krastanov, M Heuck, JH Shapiro, P Narang, DR Englund, K Jacobs
2020 First Author

Stochastic estimation of dynamical variables

Quantum Science and Technology 4 (3), 035003
S Krastanov, S Zhou, ST Flammia, L Jiang
2019 First Author

Optimized entanglement purification

Quantum 3, 123
S Krastanov, VV Albert, L Jiang
2019 First Author

Deep neural network probabilistic decoder for stabilizer codes

Scientific reports 7 (1), 1-7
S Krastanov, L Jiang

Quantum channel construction with circuit quantum electrodynamics

Physical Review B 95 (13), 134501
C Shen, K Noh, VV Albert, S Krastanov, MH Devoret, RJ Schoelkopf, SM Girvin, L Jiang

Holonomic quantum control with continuous variable systems

Physical review letters 116 (14), 140502
VV Albert, C Shu, S Krastanov, C Shen, RB Liu, ZB Yang, RJ Schoelkopf, M Mirrahimi, MH Devoret, L Jiang
2016 First Author

Universal control of an oscillator with dispersive coupling to a qubit

Physical Review A 92 (4), 040303
S Krastanov, VV Albert, C Shen, CL Zou, RW Heeres, B Vlastakis, RJ Schoelkopf, L Jiang

Cavity state manipulation using photon-number selective phase gates

Physical review letters 115 (13), 137002
RW Heeres, B Vlastakis, E Holland, S Krastanov, VV Albert, L Frunzio, L Jiang, RJ Schoelkopf

Apar-T: code, validation, and physical interpretation of particle-in-cell results

Astronomy and Astrophysics 558, A133
M Melzani, C Winisdoerffer, R Walder, D Folini, JM Favre, S Krastanov, P Messmer

Publications (preprints and in-preparation)

2022 preprint Last Author

All-Photonic Artificial Neural Network Processor Via Non-linear Optics

JR Basani, M Heuck, DR Englund, S Krastanov
2022 preprint First Co-author

A spin-optomechanical quantum interface enabled by an ultrasmall mechanical and optical mode volume cavity

H Raniwala*, S Krastanov*, M Eichenfield, DR Englund
2022 preprint

Spin-Phonon-Photon Strong Coupling in a Piezomechanical Nanocavity

H Raniwala, S Krastanov, L Hackett, M Eichenfield, DR Englund, ME Trusheim
2021 preprint First Author

Controlled-Phase Gate by Dynamic Coupling of Photons to a Two-Level Emitter

arXiv preprint arXiv:2110.02960
S Krastanov, K Jacobs, DR Englund, M Heuck
2020 preprint First Author

Unboxing quantum black box models: Learning non-Markovian dynamics

arXiv preprint arXiv:2009.03902
S Krastanov, K Head-Marsden, S Zhou, ST Flammia, L Jiang, P Narang
2020 preprint

Efficient cavity control with SNAP gates

arXiv preprint arXiv:2004.14256
T Fösel, S Krastanov, F Marquardt, L Jiang

Multiplexed control of spin quantum memories in a scalable photonic circuit

mentoring an undergrad co-author | experiment, analysis, and manuscript finished
A Golter*, G Clark*, TE Dandachi, S Krastanov, A Leenheer, N Wan, H Raniwala, M Zimmerman, M Dong, K Chen, L Li, D Dominguez, G Gilbert, M Eichenfield, DR Englund