Skip to main content

Electrical detection of nuclear spin polarization in Si/SiGe heterostructures as the first step to the Nuclear Spin Quantum Computer

Objective

The idea of quantum computation is a promising recent development. Among the proposed models especially attractive is a nuclear spin quantum computer (NSQC) based on isotopically engineered Si/SiGe hetero-structures.
In NSQC, recording information on a quantum level corresponds to polarization of nuclear spins.
However, further development of this idea is impossible without certainty that the state of nuclear spins in Si/SiGe hetero-structures can be determined electronically.
This project aims to answer this problem and therefore can be considered as the "nursery" for realization of NSQC that will have a long-term impact on the improvement of information environment.
The idea of quantum computation is a promising recent development. Among the proposed models especially attractive is a nuclear spin quantum computer (NSQC) based on isotopically engineered Si/SiGe hetero-structures.
In NSQC, recording information on a quantum level corresponds to polarization of nuclear spins.
However, further development of this idea is impossible without certainty that the state of nuclear spins in Si/SiGe hetero-structures can be determined electronically.
This project aims to answer this problem and therefore can be considered as the "nursery" for realization of NSQC which will have a long-term impact on the improvement of information environment.

OBJECTIVES
The main objectives of this project are:
1) Develop a technique for electrical detection of the state of nuclear spin polarization in Si/SiGe hetero-structure system with relatively few nuclei, which might be applied to manipulation of nuclear spin "qubits" in the possible realization of the nuclear spin quantum computer (NSQC);
2) Develop a theory of hyperfine interaction between electron and nuclear spin systems in application to the Si/SiGe heterostructures;
3) Develop alternative methods for electrical control of the state of nuclear spin polarization.

DESCRIPTION OF WORK
The experimental part of the work consists of measurements of the electron spin resonance (ESR) in isotopically engineered Ge with different abundance of non-zero nuclear spin isotope Ge-73. These measurements are aimed to reveal the intensity of hyperfine spin-spin interaction between electron localized on the shallow donor and nuclear spin of Ge-73.

Next, the longitudinal magneto resistance of two-dimensional electron gas in the quantum Hall effect regime in Si/SiGe hetero-junction will be measured. This will occur under microwave radiation corresponding to ESR in Si.
Polarization of the nuclear spins will be induced via hyperfine interaction between nuclear and electron spins.
Overhauled effect and transport measurements will be used for detection of the nuclear spin polarization as a function of temperature, magnetic field, frequency and power of microwave radiation.
This will help us to determine the optimal conditions for detection of the nuclear spin polarization that corresponds to recording and reading information on a quantum level.
Theoretical studies will focus on the investigation of the mechanisms of hyperfine interaction between electron and nuclear spins in Si- and Ge- based structures and on the development of alternative methods for detection of nuclear spin polarization in structures with small amount of nuclear spins.

Funding Scheme

ACM - Preparatory, accompanying and support measures

Coordinator

MAX-PLANCK GESELLSCHAFT ZUR FOERDERUNG DER WISSENSCHAFTEN E.V.
Address
Hofgartenstrasse 8
80539 Muenchen
Germany

Participants (1)

BAR ILAN UNIVERSITY
Israel
Address
Bar Ilan University Campus
52900 Ramat Gan