Lawrence Berkeley National Lab
Computational Chemistry, Materials and Climate Group
Current
Identifying routes to simulate chemistry problems beyond the limits of classical computing resources.
If your interested in knowing more about what I’m thinking, send me an email.
Sandia National Laboratories, Livermore
Summer 2018
With the advent of quantum computing technology there is a need to identify methods to characterize the reliability of computed solutions. My work focuses on developing quantum algorithms for near-term quantum computing devices and finding methods to verify the algorithms are being correctly mapped to quantum circuitry.
University of California, Merced
2014-2018
I spend my days working in an atomic playground. Using ultra-cold atoms, we are able to engineer and emulate quantum phenomena difficult to access in solid-state systems. We can optimize quantum transport in lattice systems, detect topological phases in quantum matter, and realize exotic forms of persistent current. I have explored these topics throughout my PhD thesis for fermions (particles with spin 1/2) in optical potentials (a lattice created by lasers).
The energy of fermions in lattice systems can be obtained using the Fermi-Hubbard model. Using computational techniques such as Exact Diagonalization, we can obtain the lowest energy state and associated ground state wave function. The ground state wave function is used to calculate observables like persistent current and can be evolved in time to discern atomic transport properties. I have found a passion for investigating physical systems using code, and I developed an aptness for transforming mathematical models into computational algorithms. Here are a selection of algorithms, coded in C++, I have used in my work:
- Exact Diagonalization of Hubbard Hamiltonian – manipulation of large, sparse arrays
- Lanczos Approximation (time-independent and time-dependent)
- 4th order Runge-Kutta to evaluate time-dependent differential equations.
By designing these algorithms and calculating complex mathematical equations I can access the quantum world. While doing so, I published a few papers (more to come) and presented as well. Take a look if you’d like to see this world for yourself. (All links are to open access copies of manuscripts)
Publications
- M. Metcalf, C.Y. Lai, M. Di Ventra, C.C. Chien (2018), “ Many-body multi-valuedness of particle-current variance in closed and open cold-atom systems,” (preprint)
- M. Metcalf, C.Y. Lai, K. Wright, C.C. Chien (2017), “Protocols for dynamically probing topological edge states and dimerization with fermionic atoms in optical potentials”, European Physics Letters. 118 56004. (ArXive)
- M. Metcalf, C.Y. Lai, C.C. Chien (2016), “Hysteresis of non-interacting and spin-orbit coupled atomic Fermi gases with dissipation”, Physical Review A 93: 053617. (ArXive)
- M. Metcalf, G.W. Chern, M. Di Ventra, C.C. Chien (2016), “Matter-wave propagation in optical lattices: geometrical and flat-band effects”, Journal of Physics B 49: 7. (ArXive)
Contributed Talks
2017a Seminar at Yale University, New Haven, CT, “Quantum Transport of Fermions in Optical Potentials.”
2017b Seminar at Dartmouth College, Hanover, NH, “Quantum Transport of Fermions in Optical Potentials.”
2017c Seminar at Sandia National Laboratories, Livermore, CA, “Quantum Transport of Fermions in Optical Potentials.”
2017d Focus session at APS DAMOP Meeting, Sacramento, CA, “Protocols for dynamically probing topological edge states and dimerization with fermionic atoms in optical potentials.”
2017e Focus session at APS March Meeting, New Orleans, LA, “Protocols for dynamically probing topological edge states and dimerization with fermionic atoms in optical potentials.”
2016a Focus session at APS March Meeting, Baltimore, MD, “Hysteresis of non-interacting and spin-orbit coupled atomic Fermi gases with dissipation.”
2016b Focus session at APS Annual Meeting of the Far West Section, Davis, CA, “Hysteresis of non-interacting and spin-orbit coupled atomic Fermi gases with dissipation.”
Poster Presentations
2016a MURI Review, Berkeley, CA, “Matter-wave propagation in optical lattices: geometrical and flat-band effects.”
2016b California Institute for Quantum Emulation, Berkeley, CA, “Matter-wave propagation in optical lattices: geometrical and flat-band effects.”
2014 Institute for Theoretical Atomic and Molecular Physics Graduate Winter School, Oracle, AZ, “Matter-wave propagation in optical lattices: geometrical and flat-band effects.”
I am providing short, technical descriptions of previous research. To provide a glimpse into the projects, posters presented at earlier conferences are attached. I have gathered a selection of photos to tell the story of my experience.
Lawrence Livermore National Laboratory
National Ignition Facility
Summer 2013
I designed and built a single-shot second harmonic frequency resolved optical gating pulse measurement device to determine the temporal and frequency pulse width, spectrum and phase for the Advanced Radiographic Capability (ARC) damage testing laser. I programmed a Matlab code to quantify measurements by resolving the shot images.
Presentations
2013 NIF Poster at Lawrence Livermore National Laboratory, Livermore, CA, “Measurement Techniques for Ultra-Short Laser Pulses”
Texas Christian University
Molecular Physics Laboratory
Summer 2011
I observed and measured the infrared absorption of SimCn and Cn molecules as they moved from their vibrational ground state to their first excited quantum state. I conducted experimental research using FTIR spectroscopy, Nd-YAG lasers (SP Quanta-Ray 1064nm) and Argon matrix trapping. Using the Gaussian program for Density Functional Theory, I predicted the molecular structure associated with the 1474 cm-1 absorption band.
Presentations
2011 Focus session at APS Annual Meeting of the Far West Section, Palo Alto, CA, “FTIR Spectroscopy and Density Functional Theory of the 1474 cm-1
2012 Summer Research Poster at Undergraduate Women in Physics Conference, Palo Alto, CA, “FTIR Spectroscopy and Density Functional Theory of the 1474 cm-1 Absorption inCn Carbon Cluster Spectra”
Mekena Metcalf 