Raman Scattering Errors in Stimulated-Raman-Induced Logic Gates in ^{133}Ba^{+}

Area of Science:

• Atomic physics
• Quantum information science
• Laser-matter interactions

Background:

• Spontaneous Raman scattering in ions can limit quantum gate fidelity.
• Previous theoretical models predicted higher scattering rates for Barium-133 ions (¹³³Ba⁺).

Purpose of the Study:

• To accurately measure the spontaneous Raman scattering rate of laser-illuminated ¹³³Ba⁺.
• To investigate the discrepancy between theoretical predictions and experimental observations.
• To determine if Raman scattering poses a fundamental limit to laser-driven quantum gates.

Main Methods:

• Illuminating ¹³³Ba⁺ ions with a far-detuned laser.
• Measuring the resulting spontaneous Raman scattering rate.
• Employing a refined theoretical treatment of the scattered photon density of states.

Main Results:

• Experimental scattering rates were found to be lower than previously estimated.
• A more accurate calculation of the photon density of states explains most of the observed discrepancy.
• The fundamental atomic physics limit from laser-induced spontaneous Raman scattering is shown to be negligible.

Conclusions:

• Laser-induced spontaneous Raman scattering does not impose a fundamental limit on laser-driven quantum gates.
• Accurate modeling of photon density of states is crucial for understanding ion-light interactions.
• This research removes a significant barrier for developing robust quantum computing technologies.