YQI Seminar - Neil Warrington - MIT

Lattice field theory for superconducting circuits

In this talk I will present a new, general method for computing properties of superconducting circuits from circuitQED. This method is essentially a direct adaptation of “lattice QCD”, a tool commonly used in particle physics to solve the microscopic equations of nuclear physics, to superconducting circuits. I will describe the method, then present applications to fluxonium. Connection to experiment is made from a microscopic study of charge noise. Small corrections to the standard coherent quantum phase slip rate formula are seen in the microscopic calculations, and I present a simple modification to the present theory that accounts for the difference. It is also seen that ground capacitances reduce charge noise.