High-connectivity SiGe quantum dot devices using the SLEDGE architecture

Si-SiGe quantum dots are a promising platform for scalable quantum computing. In order to increase the connectivity of spin qubits, it will be necessary to make a transition from conventional linear quantum dot arrays [1, 2] towards more complex geometries. One such geometry of interest is the triangular quantum dot array, where three quantum dots may be mutually exchange-coupled to one another. By eliminating interstitial field gates, a triangular dot array only requires a single metal layer of back-end routing when using the SLEDGE device architecture [2]. Here we show full configuration interaction simulations of such a triangular device, providing confidence that the device can be tuned into a state where all three dots reach single electron occupancy and provide adequate control of the exchange coupling [3,4].  We also discuss the realization of these structures and preliminary measurements.

[1] D. M. Zajac et al., Phys. Rev. Applied 6, 054013 (2016)

[2] S. Ha et al., Nano Lett. 22, 1443 (2022)

[3] A. S. Pan et al., Quantum Sci. Technol. 5, 034005 (2020)

[4] C. R. Anderson et al., AIP Advances 12, 065123 (2022)