Towards topological spin qubits based on graphene nanoribbons using a UHV microscopic tool

Graphene nanoribbons (GNRs) are now routinely created using bottom-up synthesis of monomers that polymerize on Au(111) surfaces [1]. A growing library of GNRs is available with a wide range of electronic and magnetic properties [2]. New families of GNRs have recently been synthesized with predicted spintronic and topological properties [3]. Electrical gating of these GNRs is important for future quantum computing applications and may be achieved using LaAlO3/SrTiO3 (LAO/STO) [4] and/or graphene devices. Our research aims to integrate GNRs with these two other platforms under ultra-high vacuum (UHV) conditions. We use a UHV instrument that integrates an evaporator for depositing GNR monomers, a variable-temperature AFM/STM for atomic-scale characterization of the GNRs, and Ultra-Low Voltage E-beam Lithography (ULV-EBL) for programming the nanostructures on LAO/STO [5]. Our central challenge is to create GNRs on oxide surfaces and control their properties using local electric fields from the reconfigurable LAO/STO platform.

[1] Cai, J., et al. Nature 466, 470–473 (2010)

[2] Chen, Z., et al. Adv. Mater. 32, 2001893 (2020)

[3] Huang, H., et al. arXiv: 2406.13978 (2024)

[4] Cen, C., et al. Science 323, 1026–1030 (2009)

[5] Yang, D. et al., Appl. Phys. Lett. 117, 253103 (2020)