@phdthesis{bibcite_106,
  author = {Lev Krayzman},
  title = {Thin-film 3D Resonators for Superconducting Quantum Circuits},
  abstract = {<p>Quantum computing has garnered a lot of attention due to the belief that it would be<br>able to solve certain kinds of problems which are intractable to classical computers.<br>One of the leading candidate platforms for quantum computing is superconducting<br>circuits. Within this platform, there are two main methods of storing quantum infor-<br>mation: Josephson-junction based artificial atoms and harmonic oscillators. The large<br>Hilbert space of the bosonic excitations of a harmonic oscillator allows for redundant<br>storage of quantum information. Quantum error correction in a single mode using<br>bosonic codes has been demonstrated beyond break-even. However, devices with<br>more than a handful of oscillators have not yet been demonstrated. One of the main<br>challenges in scaling up devices is oscillator design. Currently, coaxial stub cavities<br>machined from high-purity aluminium are most commonly used. Fully-lithographic<br>micromachined cavities have previously been demonstrated, but had short lifetimes<br>due to loss in the seams. In this thesis, I describe a way to fabricate and measure<br>ultra-high-quality microwave seams using indium bump-bonding. I then discuss the<br>application of this to micromachined cavities, improving their lifetime hundredfold<br>and exceeding that of stub cavities. I also demonstrate suspended coaxial resonators,<br>which have a demountable centre conductor. They are easier to make than micro-<br>machined cavities and can slightly exceed stub cavities{\textquoteright} lifetime without the use of<br>high-purity aluminium. Finally, I discuss recent work on ways of measuring the losses<br>of different materials or interfaces using multimode resonators, and the comparison<br>of this to traditional materials studies methods.</p>},
  year = {2022},
  journal = {Physics},
  volume = {Ph.D.},
  publisher = {Yale University},
  address = {New Haven},
  url = {https://rsl.yale.edu/sites/default/files/files/RSL_Theses/2022-Thesis-Lev-Krayzman(1).pdf},
}