Majorana zero modes and qubit: Challenges and solutions
Speaker: 刘 东 (University of California)
Time: April 06, 2017 10:00
Topological materials provide a protection from decoherence at the hardware level by using emergent non-Abelian anyons. The simplest non-Abelian anyon involves a defect that binds a Majorana zero-energy mode, predicted to appear quite naturally in certain superconducting systems. Direct tunneling spectroscopy method provides the simplest way to measure the presence of the zero-energy state at the defect. However, the zero-bias peak in tunneling conductance might originate from the other mechanisms giving false-positive signatures. In this talk, I will introduce two simple measurement schemes to overcome the problem, and show robust, clear, and universal experimental signatures of MZMs.
Majorana zero modes provide a potential platform for the storage and processing of quantum information with intrinsic error rates that decrease exponentially with inverse temperature and with the length scales of the system. However, it is less well-understood how error rates depend on the speed with which non-Abelian quasiparticles are braided. In general, diabatic corrections only vanish as a power-law function with the length of time for the braid. This power-law behavior can wash out the advantages of topological quantum computation. In this talk, I will show that such diabatic errors can be detected and corrected by applying a sequence of parity measurements.