Accession Number:

AD1101420

Title:

Suppressing Qubit Dephasing Using Real time Hamiltonian Estimation

Descriptive Note:

Journal Article - Open Access

Corporate Author:

Harvard University Cambridge United States

Report Date:

2014-10-08

Pagination or Media Count:

6.0

Abstract:

Unwanted interaction between a quantum system and its fluctuating environment leads to decoherence and is the primary obstacle to establishing a scalable quantum information processing architecture. Strategies such as environmental and materials engineering, quantum error correction and dynamical decoupling can mitigate decoherence, but generally increase experimental complexity. Here we improve coherence in a qubit using real-time Hamiltonian parameter estimation. Using a rapidly converging Bayesian approach, we preciselymeasure the splitting in a singlet-triplet spin qubit faster than the surrounding nuclear bath fluctuates. We continuously adjust qubit control parameters based on this information, thereby improving the inhomogenously broadened coherence time T 2 from tens of nanosecondsto 42 ms. Because the technique demonstrated here is compatible with arbitrary qubit operations, it is a natural complement to quantum error correction and can be used to improve the performance of a wide variety of qubits in both meteorological and quantuminformation processing applications.

Subject Categories:

  • Quantum Theory and Relativity

Distribution Statement:

APPROVED FOR PUBLIC RELEASE