Proposal for a Deterministic Solid-State Quantum Memory
Abstract
One of the major limitations of several quantum technologies, e.g. quantum computation and quantum networks, is a suitable high performance quantum memory that allows efficient interconversion between optical ~flying qubits~ and stationary memory qubits with sufficiently high quantum coherence and long storage times. One of the most promising solid state quantum memory approaches has for some time ben semiconductor quantum dots. The flying qubits produced by them have excellent optical properties; however, the drawback has been the very short coherence times available. The fundamental noise mechanism in these quantum dots has been known to be the relatively strong spin coupling of the quantum dot~s electron and the spins of the surrounding nuclei in the local environment of the electron. This spin bath has significant thermal fluctuations, thus significantly reducing the achievable coherence time for quantum dots. Alternate approaches to quantum memories, e.g. using NV centers in diamonds, achieve higher coherence and storage times at the expense much lower transfer efficiency converting flying qubits into stored qubits ~ i.e. very low input/output rates. The state of the art I/O rate for these longer storage time quantum memories is about 5 Hz. The PI has recently demonstrated (Science, Volume 364, 62 2019) a breakthrough in which the surrounding nuclear ensemble can be optically cooled much as in atomic laser cooling. Furthermore, after cooling, the ensemble~s nuclear spin state can be controlled such that the state of the quantum dot electron can transferred to and stored in the nuclear ensemble. Therefore, what was a fundamental impediment to the performance of the quantum dot as a memory can be turned into an aid that increases the lifetime of the stored quantum information. The proposed research will take the recently demonstrated techniques and optimize them in order to demonstrate the first near deterministic, controllable, long storage time quantum memory with high quality optical properties. If successful, this research will represent a very significant lead ahead in building useful quantum memories for quantum networking and quantum computation applications. The PI and his team are world class researches with an outstanding track record in this field. Based on their track record, I judge that this research team has a high likelihood of achieving the ambitious goals of in the proposal. The team~s facilities at the Cavendish Laboratory are equally world class. The proposed costs for the project are well aligned with the goals and methods for the proposed research.
Document Details
- Document Type
- DoD Grant Award
- Publication Date
- Aug 20, 2019
- Source ID
- N629091912115
Entities
People
- Mete Atatüre
Organizations
- Office of Naval Research
- United States Navy
- University of Cambridge