State-conditional coherent charge qubit oscillations in a Si/SiGe quadruple quantum dot
Journal Article
·
· npj Quantum Information
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics; Seoul National Univ. (Korea, Republic of). Dept. of Physics and Astronomy
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Materials Science and Engineering
- Univ. of Wisconsin, Madison, WI (United States). Dept. of Physics
Universal quantum computation requires high-fidelity single-qubit rotations and controlled two-qubit gates. Along with high-fidelity single-qubit gates, strong efforts have been made in developing robust two-qubit logic gates in electrically gated quantum dot systems to realise a compact and nanofabrication-compatible architecture. Here we perform measurements of state-conditional coherent oscillations of a charge qubit. Using a quadruple quantum dot formed in a Si/SiGe heterostructure, we show the first demonstration of coherent two-axis control of a double quantum dot charge qubit in undoped Si/SiGe, performing Larmor and Ramsey oscillation measurements. We extract the strength of the capacitive coupling between a pair of double quantum dots by measuring the detuning energy shift (≈75 μeV) of one double dot depending on the excess charge configuration of the other double dot. Finally, we further demonstrate that the strong capacitive coupling allows fast, state-conditional Landau–Zener–Stückelberg oscillations with a conditional π phase flip time of about 80 ps, showing a promising pathway towards multi-qubit entanglement and control in semiconductor quantum dots.
- Research Organization:
- Sandia National Lab. (SNL-NM), Albuquerque, NM (United States); Univ. of Wisconsin, Madison, WI (United States)
- Sponsoring Organization:
- Army Research Office (ARO) (United States); Dept. of Defense (DOD) (United States); Dept. of the Navy (DON) (United States). Office of Naval Research (ONR); Korea Inst. of Science and Technology (KIST) (Korea, Republic of); National Science Foundation (NSF) (United States); USDOE Laboratory Directed Research and Development (LDRD) Program; USDOE National Nuclear Security Administration (NNSA); USDOE Office of Science (SC), Basic Energy Sciences (BES) (SC-22)
- Contributing Organization:
- Seoul National Univ. (Korea, Republic of)
- Grant/Contract Number:
- AC04-94AL85000; FG02-03ER46028
- OSTI ID:
- 1340242
- Alternate ID(s):
- OSTI ID: 1356176
- Report Number(s):
- SAND2016--3914J; npjqi201632
- Journal Information:
- npj Quantum Information, Journal Name: npj Quantum Information Vol. 2; ISSN 2056-6387
- Publisher:
- Nature Partner JournalsCopyright Statement
- Country of Publication:
- United States
- Language:
- English
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