Nuclear Spins in Nanostructures

TL;DR

This review discusses recent advances in understanding and manipulating nuclear spins in nanostructures like quantum dots and defect centers, highlighting their impact on quantum information processing and decoherence control.

Contribution

It summarizes recent theoretical and experimental progress in controlling nuclear spins in nanostructures, emphasizing new methods for decoherence mitigation and nuclear state manipulation.

Findings

Understanding of spin-bath decoherence mechanisms

Advances in nuclear spin polarization techniques

Development of nuclear state narrowing methods

Abstract

We review recent theoretical and experimental advances toward understanding the effects of nuclear spins in confined nanostructures. These systems, which include quantum dots, defect centers, and molecular magnets, are particularly interesting for their importance in quantum information processing devices, which aim to coherently manipulate single electron spins with high precision. On one hand, interactions between confined electron spins and a nuclear-spin environment provide a decoherence source for the electron, and on the other, a strong effective magnetic field that can be used to execute local coherent rotations. A great deal of effort has been directed toward understanding the details of the relevant decoherence processes and to find new methods to manipulate the coupled electron-nuclear system. A sequence of spectacular new results have provided understanding of spin-bath decoherence, nuclear spin diffusion, and preparation of the nuclear state through dynamic polarization and more general manipulation of the nuclear-spin density matrix through "state narrowing". These results demonstrate the richness of this physical system and promise many new mysteries for the future.