Geometric phase detection via NMR interferometry

Area of Science:

• Nuclear Magnetic Resonance (NMR) Spectroscopy
• Quantum Mechanics
• Condensed Matter Physics

Background:

• Geometric phase, or Berry/Aharonov-Anandan phase, is a fundamental concept in quantum mechanics.
• Detecting geometric phase in bulk ensembles using NMR has been challenging.
• Spin coherence holonomy offers a potential pathway for such measurements.

Purpose of the Study:

• To introduce a novel benchtop NMR method for detecting geometric phase.
• To utilize spin coherence holonomy for phase measurement in bulk ensembles.
• To establish a practical foundation for probing geometric phase effects in NMR.

Main Methods:

• Development of a benchtop NMR technique using phase-wound echo trains.
• Employing consecutive π pulses with cyclic phase incrementation to drive spinor trajectories.
• Utilizing parity-based analysis to isolate geometric phase and cancel dynamical offsets.

Main Results:

• Demonstrated interferometric detection of geometric phase via spin coherence holonomy.
• Observed a linear increase in extracted phase with echo number and sign reversal upon winding reversal.
• Confirmed phase independence from echo time in the adiabatic regime.
• Showcased robustness to B₀ gradients and diffusion in low-field, inhomogeneous conditions.

Conclusions:

• The developed NMR method provides a practical approach for measuring geometric phase.
• The technique is robust and applicable under challenging experimental conditions.
• This work opens avenues for exploring non-adiabatic transport, heterogeneous systems, and quantum sensing applications.