Experimental demonstration of a controlled-NOT wave-packet gate

Area of Science:

• Quantum Information Science
• Atomic Physics
• Quantum Computing

Background:

• Quantum logic gates are fundamental building blocks for quantum computation.
• Previous implementations of the controlled-NOT (CNOT) gate in ion traps have limitations, including sensitivity to Stark shifts and the need for auxiliary internal levels.

Purpose of the Study:

• To experimentally demonstrate a novel controlled-NOT (CNOT) quantum logic gate.
• To implement a CNOT gate between the motional and internal-state qubits of a single ion.
• To develop a CNOT gate with enhanced robustness and simplified requirements.

Main Methods:

• Experimental demonstration of a CNOT quantum logic gate using a single ion.
• Conditional dynamics dependent on the extent of the ion's wave packet.
• Characterization of gate logic via postgate ion state population measurements for various input states.
• Demonstration of gate coherence using an interferometric measurement.

Main Results:

• Successful experimental demonstration of a CNOT quantum logic gate between motional and internal-state qubits.
• The implemented CNOT gate exhibits conditional dynamics influenced by the ion's wave packet extent.
• The gate shows immunity from Stark shifts and does not require an auxiliary internal level, unlike previous methods.

Conclusions:

• This work presents a significant advancement in the experimental realization of robust quantum logic gates.
• The demonstrated CNOT gate offers practical advantages for building scalable quantum information processors.
• The approach paves the way for more reliable and efficient quantum computation using trapped ions.