Collaborative Research: Adiabatic Quantum Computing in Open Systems: Methodology, Performance, and Error Correction

University Of Southern California, Los Angeles CA

Investigators

Abstract

Quantum computation is a burgeoning field of tremendous promise. It is perhaps best known for two breakthrough algorithms discovered a decade ago, one for cracking public key cryptography and another for fast solutions to optimization problems. Quantum computers can directly solve the equations of quantum mechanics, and so are believed to hold the key to ab initio drug design and materials engineering. This research involves a model called adiabatic quantum computation (AQC) that has attracted the attention of various groups attempting to build quantum computers, especially using superconducting devices. The AQC approach to computation is particularly well suited to optimization problems, since unlike an ordinary "classical" computer, the adiabatic quantum computer can simultaneously explore a multitude of possibilities while tunneling through barriers, as it is searching for the optimal solution. The potential of AQC is exciting, but there are crucial missing elements in AQC theory. Most importantly, the theory of AQC error correction is still primitive, even though error correction will undoubtedly be indispensable for a working AQC. The reason is that quantum computers are particularly sensitive to their interactions with the environment, through a process called decoherence, that rapidly erases their computational power by introducing errors and noise. This research involves the development of a theory of error correction for AQC, as well as detailed insight into specific physical systems that could be used to realize a fault tolerant AQC. At the same time, this research addresses AQC's potential for new algorithms and insight into physical processes like quantum phase transitions. To thoroughly explore error correction in AQC, the investigators are using their experience with noiseless subsystems, dynamical decoupling, and quantum error correcting codes.