NANOMAGIQC

Project Presentation

Project details

Contract number: IST-2001-33186

Project acronym: NANOMAGIQC

Project name: Nanotechnology and Magnetic Qubits To Implement Quantum Computation

Action line: IST-2001-6.2.1

Project logo: see upper left corner.

Total cost: 2,443,706 euro

Commission funding: 1,468,000 euro

List of participants

1. Universitat de Barcelona (UB), Spain.
2. National Physical Laboratory (NPL), UK.
3. Consejo Superior de Investigaciones Científicas (CSIC), Spain.
4. Hewlett Packard European Laboratories (HPLB), UK.

Coordinator contact details

Prof. Javier Tejada
Dept. Física Fonamental
Facultat de Física
Universitat de Barcelona
Avda. Diagonal 647
08028 Barcelona (Spain)

Tlf.: 34 93 402 11 55
Fax: 34 93 402 11 49
e-mail: jtejada@ubxlab.com

Objectives

The main objective of this work is the first detailed investigation of the prospects of joining nanotechnology devices and magnetic systems for quantum information and storage.

Our proposal addresses five key points which evolve from the construction ofnanodevices for detection and measurement of mesoscopic spin to the construction of quantum logic gates of one and two magnetic qubits.

In between, we aim to search for magnetic mesoscopic systems owing two levels(molecular clusters and nanoparticles) which may be mixed at frequencies ranging from MHz to GHz.

The decoherence phenomena associated to both intrinsic properties of the molecules/particles and to the interaction of the qubits with the substrate will be studied with the aim of controlling the life time and, therefore, the operation time of the qubits.

Brief work description

The first work to be carried out is the construction of microSQUIDs, microHall probes and other nanodevices which should be capable to detect and measure mesoscopic spin ranging between thousand and few hundred times the Planck’s constant.

We want to prepare new magnetic molecules and antiferromagnetic particleswith controlled values of the total net spin and narrow size distribution. These magnetic systems will be characterised using structural and magnetic methods to determine the values of the spin, anisotropy barrier height, tunneling rate and the quantum coherence splitting.

The positioning of both molecules and particles onto microSQUIDs and microHall probes will be worked out by using atomic and magnetic force microscopy.

The quantum splitting associated to the spin quantum coherence as well as thefrequency for the spin precession will be measured in the case of molecules/particles enriched with non nuclear spin isotopes and deposited on selected substrates. The aim is to establish the correlation that exists between the coherence time and the structural and magnetic properties of the clusters/particles.

The experimental work on decoherence will be supported by theory and simulations. The construction of one- and two-qubit quantum logic gates will be done by arranging the resonances of the qubits to be covered by the range of frequencies of the coupled SQUID.

The control of the entanglement between two qubits will be performed by coupling the qubits with a superconducting coil -this generates an interaction Hamiltonian capable of generating entanglement.

Milestones and expected results

1. Construction of new nanotechnology-based sensors to detect and measure the quantum state of molecular clusters and nanoparticles.
2. Investigation of these systems, including enrichment with non-nuclear spin isotopes, and deposition and positioning onto selected substrates.
3. Experimental and theoretical study of decoherence phenomena.
4. Construction of quantum logic gates using magnetic particles and microSQUIDs (leading to entanglement).
5. Ultrasensitive magnetic measurements, using the new nanotechnology-based sensors.