Ultrafast universal quantum control of a quantum-dot charge qubit using Landau-Zener-Stückelberg interference.
A basic requirement for quantum information processing is the ability to universally control the state of a single qubit on timescales much shorter than the coherence time. Although ultrafast optical control of a single spin has been achieved in quantum dots, scaling up such methods remains a challenge. Here we demonstrate complete control of the quantum-dot charge qubit on the picosecond scale [corrected], orders of magnitude faster than the previously measured electrically controlled charge- or spin-based qubits. We observe tunable qubit dynamics in a charge-stability diagram, in a time domain, and in a pulse amplitude space of the driven pulse. The observations are well described by Landau-Zener-Stückelberg interference. These results establish the feasibility of a full set of all-electrical single-qubit operations. Although our experiment is carried out in a solid-state architecture, the technique is independent of the physical encoding of the quantum information and has the potential for wider applications.
Key Laboratory of Quantum Information, Department of Optics and Optical Engineering, University of Science and Technology of China, Chinese Academy of Sciences, Hefei 230026, China.
Gang
G
Cao
Hai-Ou
HO
Li
Tao
T
Tu
Li
L
Wang
Cheng
C
Zhou
Ming
M
Xiao
Guang-Can
GC
Guo
Hong-Wen
HW
Jiang
Guo-Ping
GP
Guo