Quantum Engineering of Fractional Hall Physics in an Atom-Optical Laughlin-Pump Oscillator

Open Access
Liu, Qi
Graduate Program:
Doctor of Philosophy
Document Type:
Date of Defense:
May 15, 2018
Committee Members:
  • Nathan David Gemelke, Dissertation Advisor
  • Nathan David Gemelke, Committee Chair
  • David Scott Weiss, Committee Member
  • Kenneth O'Hara, Committee Member
  • Venkatraman Gopalan, Outside Member
  • Quantum Simulation
  • Topological Order
  • Laughlin's Quantum Pump
  • Driven Oscillator
  • Sagnac Interferometer
Quantum simulation in cold atomic physics has seen successes in many different fields and contexts of research. Simulation of gauge effects, often introduces new challenges, often originating from time-dependent potentials used to approximate new Hamiltonians. To overcome such obstacles, this thesis describes the innovation of a new method, named quantum Engineering by Amplified Stimulated Excitation (quEASE), for its use in an analogy between engineered coherent many-body states and the operation of a maser or a laser. By incorporating an ultra-cold atomic gas into an oscillator loop and driving the system into stable oscillation, a coherent mode of this many-body physical system can be engineered, and specific modes may be chosen through design of generalized filters used in the feedback loop. In particular, this thesis demonstrates an application of the quEASE method in the interrogation of Fractional Quantum Hall physics in cold atom systems, in which an optical pump oscillator is constructed based on an optical realization of Laughlin's charge pump topology[1]. A pair of interferometers are coupled to each other by interacting with a common gas of atoms, in which time-reversal symmetry breaking modulation is transferred from one beam to another. The dynamics resemble essential features in electronic quantum Hall measurements, such as the transverse field and flux bound to particles. This experiment establishes a first direct transport measurement attempt in quantum simulation of fractional quantum Hall physics in cold atomic systems. A novel driven-oscillator scheme for probing the optical quantum pump oscillator is developed to overcome difficulties originating from weak coupling between light and atoms.