# Cassidy Berk

> Software Engineer / Quantum Information Science

Location: Santa Cruz, California, United States
Profile: https://flows.cv/cassidyberk

## Work Experience
### Software Engineer @ Rigetti Computing
Jan 2021 – Present

### Postdoctoral Researcher @ Berkeley Lab
Jan 2019 – Jan 2021
Advanced Quantum Testbed (AQT)
Built High-Throughput Materials Characterization Pipeline in Python: “Statistical Observation of Quantum Decoherence” (StOQD) 
•	Optimized experimental data collection using Gaussian Process Regression
•	Automated XPS analysis and low temperature quantum device characterization 
•	Data/Results stored in centralized repository in HDF5
•	Custom sample representation syntax for statistical comparison/machine learning on samples

Using StOQD, improved Quality Factor of superconducting quantum resonators by factor of 5 through interface engineering and cross-correlation analysis of materials/electrical properties
•	Performed X-Ray Photoelectron Spectroscopy on superconducting quantum devices
•	Interpreted experimental results through mathematical modelling of superconducting quantum device behavior as well as error estimation using Bayesian error estimation and Monte Carlo Methods.
•	Worked collaboratively with theorists and experimentalists to improve experimental design. 

Developed XPS python package 
•	Deconvolution of spectral peaks and cross-correlation of atomic compounds across multiple spectra
•	Various machine learning tools implemented: LDA, QDA, PCA, Non-Negative Matrix factorization and Nerural Network for parameter initialization
•	High quality visualization capabilities using matplotlib
•	PyQt GUI Application

Coordinated presentation of results from all aspects of the AQT

### Graduate Research Assistant @ UC Santa Cruz
Jan 2012 – Jan 2019
Mathematical Modeling
• Modeled the energy transfer between electron, spin & lattice subsystems after femtosecond laser excitation
• Simulated the rapid thermal expansion & subsequent vibrational dynamics of nanostructures
• Visualized the spatial character of spin waves in nanomagnets excited by surface acoustic waves
• Modeled energy transfer and lattice dynamics of ferrimagnetic systems subject to femtosecond laser excitation using mean-field theory
• Derived 2nd principal equation describing magnon-phonon dynamics in nanostructures

Experimental Data Analysis
• Used techniques such as background subtraction, digital filtering, FFT, least-squares regression, & Monte Carlo methods to analyze of magnetic & acoustic dynamics 
• Fit spin-wave dispersion using the LLG equation to estimate magnetic parameters
• Fit and analyzed magnon-phonon coupling within individual nanostructures

Experimental Data Acquisition
• Performed time-domain measurements of the picosecond spin dynamics & vibrational modes in isolated nanostructures, arrays, & thin films via ultrafast magneto-optic spectroscopy
• Maintained 1.6 Watt Ti:Sapphire laser oscillator system & second harmonic generation cavity
• Measured dynamic μrad polarization rotations using lock-in modulation & differential detection
• Built autonomous experimental setup using LabVIEW, MATLAB, & instrument-specific software to record/analyze data & interface with equipment such as mechanical delay lines, lock-in detectors, digital multimeters, cameras, sensors, electromagnets, & piezoelectric actuators
• Designed & characterized kinetic optical systems with sub-micron precision & femtosecond resolution 
• Built an ultrafast laser setup to optically control the magnetization of thin films with micron precision via helicity-dependent switching - included a wide-field magneto-optic microscope to image magnetic domains
• Designed & fabricated phononic & magnetic nanostructures to implement novel characterization techniques

### Research Assistant @ Georgetown University
Jan 2009 – Jan 2012 | Washington D.C.
•	Built free-space optical setup using a Nd:YAG laser to measure optical power limiting of various hyper-branched polymers.
•	Fabricated and characterized organic-nano particles of TCNQ-Perylene for potential use as LEDs and Photovoltaics


## Education
### Doctor of Philosophy - PhD in Electrical Engineering
UC Santa

### Bachelor of Science - BS in Physics, Mathematics
Georgetown University


## Contact & Social
- LinkedIn: https://linkedin.com/in/cassidy-berk-30996699

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Source: https://flows.cv/cassidyberk
JSON Resume: https://flows.cv/cassidyberk/resume.json
Last updated: 2026-04-10