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Observation of topological transitions in interacting quantum circuits
P Roushan1, C Neill1, Yu Chen1
1Department of Physics, University of California, Santa Barbara, California 93106-9530, USA.
Nature
|November 14, 2014
Summary
We developed a new quantum circuit method to experimentally probe topological properties in quantum systems. This technique visualizes spin textures and reveals interaction-induced topological phases, advancing condensed-matter physics.
Area of Science:
- Condensed-matter physics
- Quantum information science
- Quantum simulation
Background:
- Topology plays a crucial role in understanding natural phenomena and has redefined the conception of phases of matter.
- Direct experimental probing of topological ordering in quantum systems remains a significant challenge due to limitations of current indirect methods.
Purpose of the Study:
- To develop and demonstrate a novel experimental platform using superconducting quantum circuits for investigating topological properties of quantum systems.
- To overcome the limitations of indirect experimental tools for fundamental studies of topology in physics.
Main Methods:
- Utilizing superconducting quantum circuits for precise control over quantum systems.
- Inferring geometric curvature by measuring quantum trajectory deflections in curved Hamiltonian spaces.
- Applying a quantum analogue of the Gauss-Bonnet theorem by integrating curvature to reveal topological properties.
- Benchmarking the technique with the Haldane model and extending it to interacting quantum systems with a new qubit architecture.
Main Results:
- Successfully mapped the momentum space of the Haldane model to a single-qubit Hamiltonian parameter space.
- Constructed a topological phase diagram and visualized microscopic spin textures and their evolution during phase transitions.
- Demonstrated the study of topology in an interacting quantum system, discovering an interaction-induced topological phase.
- Established a powerful and generalizable experimental platform for quantum topology studies.
Conclusions:
- The developed quantum circuit technique provides a powerful and versatile experimental platform for exploring topological phenomena in both non-interacting and interacting quantum systems.
- This method enables direct visualization and fundamental understanding of topological properties, advancing the field of condensed-matter physics and quantum information science.
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