Experimental measurement of the quantum geometric tensor using coupled qubits in diamond

• 来源期刊: 国家科学评论（英文版）
• 关键词: quantum geometry topological physics quantum measurement quantum control quantum information
• 年，卷（期）: 2020,（2）
• 页码范围: 254-260
• 页数: 7页
• 语种: 英文
• DOI: 10.1093/nsr/nwz193

摘要

Geometry and topology are fundamental concepts,which underlie a wide range of fascinating physical phenomena such as topological states of matter and topological defects.In quantum mechanics,the geometry of quantum states is fully captured by the quantum geometric tensor.Using a qubit formed by an NV center in diamond,we perform the first experimental measurement of the complete quantum geometric tensor.Our approach builds on a strong connection between coherent Rabi oscigations upon parametric modulations and the quantum geometry of the underlying states.We then apply our method to a system of two interacting qubits,by exploiting the coupling between the NV center spin and a neighboring 13C nuclear spin.Our results establish coherent dynamical responses as a versatile probe for quantum geometry,and they pave the way for the detection of novel topological phenomena in solid state.