Tunable interdot coupling in SiMOS architectures over more than nine orders of magnitude

Silicon MOS and Silicon-Germanium heterostructures have been proven as a viable route for scalable solid-state quantum computing [1]. Single-qubits operation can routinely exceed 99% [2,3] and have coherence time exceeding few ms. For two-qubit gates, fidelities reaching 98% for electrons in Silicon have been shown [4], but the strength of the Heisenberg exchange interaction, mainly controlled by the tunnel rate between the two hosting dots, remains hard to control.

We report here a gate tunable tunnel rate between two hole-quantum dots that can be continuously tuned from few Hz up to few GHz. This amount of control over the tunnel rate allows for easy spin readout by spin dependent tunneling, as well as controllable two-qubit gates.

 

 

[1] N.W. Hendrickx et al., Nature 591, 580 (2021)

[2] J. Yoneda et al., Nature Nanotech 13, 102 (2018)

[3] C. H. Yang et al., Nat Electron 2, 151 (2019)

[4] W. Huang et al., Nature 569, 532 (2019)