Skip to main content

Development of quantum computer hardware based on rare-earth-ion-doped inorganic crystals

Objective

We propose to experimentally demonstrate that reliable quantum computer (QC) hardware can be built with rare-earth-ion-doped inorganic crystals (RE crystals). We claim that RE crystals at liquid helium temperatures have exceptionally favourable properties as quantum computer hardware and present a scheme for controlled logic and quantum computations in liquid helium cooled RE crystals. Specifically we wish to use RE crystals to successfully demonstrate initial steps towards performing the first CONTROL-NOT quantum gate in a solid-state material.
Our intention with this FET-Open assessment project proposal is to demonstrate that the proposed scheme works and thereby establish RE crystals as a highly competitive candidate for quantum hardware. When this has been done we foresee the formation of a large-scale project with participating groups in theory, material science and laser development to develop more versatile QC hardware based on RE crystals.
We propose to experimentally demonstrate that reliable quantum computer (QC) hardware can be built with rare-earth-ion-doped inorganic crystals (RE crystals). We claim that RE crystals at liquid helium temperatures have exceptionally favourable properties as quantum computer hardware and present a scheme for controlled logic and quantum computations in liquid helium cooled RE crystals. Specifically we wish to use RE crystals to successfully demonstrate initial steps towards performing the first CONTROL-NOT quantum gate in a solid-state material.
Our intention with this FET-Open assessment project proposal is to demonstrate that the proposed scheme works and thereby establish RE crystals as a highly competitive candidate for quantum hardware. When this has been done we foresee the formation of a large-scale project with participating groups in theory, material science and laser development to develop more versatile QC hardware based on RE crystals.

OBJECTIVES
Decoherence times and ion-ion interactions of rare-earth ion transition in rare-earth-ion-doped inorganic crystals are well characterised. Based on this existing knowledge the present quantum computing project can therefore be aimed directly at making simple quantum computer hardware based on such crystals as described in steps A-F below.
A: The project will first focus on controlled movement of selected atomic subgroups between different hyperfine levels through frequency selective laser excitation.
B: Electric dipole-dipole interaction between the subgroups will then be studied by exciting the atoms in one subgroup to an upper state and using spectral hole-burning techniques to detect the effect of this excitation on an atomic subgroup at an other absorption frequency.
C: Optimum excitation pulses for efficient coherence and population transfer between ground state hyperfine levels and excited states will be experimentally determined. These are needed for the final qubit preparation and for quantum gate operations.
D: A novel specially designed optical pumping scheme will be applied to select only ions that interact with each other and remove non-interacting ions. As soon as this step is performed successfully the qubit preparation in the RE crystals is done.
E: A critical analysis of remaining obstacles that might need to be overcome in order to demonstrate a CONTROL-NOT gate is performed.
F: Since quantum computing hardware based on the scheme described in this proposal has not been discussed previously, theoretical work on the performance of a larger scale system based on this approach will be carried out in parallel.

Funding Scheme

ACM - Preparatory, accompanying and support measures

Coordinator

LUNDS UNIVERSITET
Address
Paradisgatan 5C
221 00 Lund
Sweden

Participants (2)

AARHUS UNIVERSITET
Denmark
Address
Nordre Ringgade 1
8000 Aarhus
CENTRE NATIONAL DE LA RECHERCHE SCIENTIFIQUE
France
Address
3, Rue Michel-ange
75794 Paris Cedex 16