YQI Seminar - Hoi-Kwan (Kero) Lau - University of Chicago

Event time: 
Tuesday, April 10, 2018 - 11:00am to 12:00pm
YQI Seminar Room - 4th Floor See map
17 hillhouse Avenue
Event description: 

What is actually needed to quantum-compute with harmonic oscillators?

To implement quantum computers on harmonic oscillator liked systems, the conventional approach is to: 1) Cool the system to the ground state; 2) Specify two physical states as the encoding basis of a qubit; 3) Implement logic gates by engineering encoding-specific interaction.  In our recent works, we show that all of these procedures are sufficient but not necessary.  Specifically, we find a unified operation that can implement logic gates for any encoding.  The formalism permits a new class of encoding that a pure logical qubit is represented by a mixed physical state.  Because the purity of quantum system is not essential, the requirement of ground-state cooling can be relaxed.  Additionally, our formalism can reduce the initialisation energy, and protect the logical qubit against a wider class of noise.