Nuclear Magnetic Resonance (NMR)-based quantum computing devices have been successful in controlling small numbers of spin qubits. However, it is extremely challenging to build a scalable NMR quantum computer; the spin polarization bias in a typical experimental setup is very low at thermal equilibrium, giving a highly mixed qubit, and the polarization decreases exponentially in the number of qubits. Moreover, in order to achieve fault tolerance, one must be able to dynamically supply pure ancilla qubits. Heat Bath Algorithmic Cooling (HBAC) is an implementation independent cooling method that combines reversible entropy compression and interaction with the cold external bath. It is capable of cooling a qubit of interest far beyond the bath polarization. Electron spins possess higher polarization and faster relaxation rate than nuclear spins under similar experimental conditions, and thus can be used as the heat bath while nuclear spins encode system qubits. In this talk, I will present our progress towards achieving high polarization of nuclear spin qubits using an electron spin and HBAC. In addition, I will show how this will be used in future for the experimental realization of multiple rounds of three-qubit quantum error correction.

 

 

Kyungdeock is a PhD student in Physics at University of Waterloo and Institute for Quantum Computing under the supervision of Dr. Raymond Laflamme and Dr. Jonathan Baugh. His main research interest is spin based implementation of quantum information processing.