Two qubit randomized benchmarking of quantum dot spin qubits

Speaker: 
Mr Wister Huang
From: 
CQC2T at UNSW
When: 
4pm Thursday 12 April 2018
Where: 
CQC2T Conference Room, Level 2, Newton Building J12, UNSW Kensington Campus

Qubits encoded in the electron spin states of gate-defined quantum dots are promising because of their long coherence time. Recent experiments have realized both single qubit operations with fault-tolerant fidelity [1-2] and two qubit logic gates [3-5]. For single qubit gates, randomized benchmarking has emerged as a popular characterization tool. However, for two-qubit gates it has so far only been applied to a few qubit implementations. This is because, in contrast to more fundamental characterization methods like state tomography of Bell states, two-qubit randomized benchmarking requires sequences of significant numbers of qubit operations to be completed with non-vanishing fidelity. Here, we demonstrate two-qubit randomized benchmarking with an average Clifford gate fidelity of 78.9 %. Our results demonstrate the coherent execution of arbitrary two-qubit algorithms on our device and evidence the capabilities of silicon-based quantum computation.

[1] M. Veldhorst et al., Nature Nanotech. 9, 981–985 (2014).
[2] J. Yoneda et al., Nature Nanotech 13, 102–106 (2018).
[3] M. Veldhorst et al., Nature 526, 410–414 (2015).
[3] TF. Watson et al., Nature 555, 633–637 (2018).
[3] DM. Zajac et al., Science 359, 439–422 (2018).