Detecting Larmor Precession of a Single Spin with a Spin-Polarized Tunneling Current

• 来源期刊: 中国物理快报（英文版）
• 年，卷（期）: 2013,（1）
• 页码范围: 187-190
• 页数: 4页
• 语种: 英文
• DOI: 10.1088/0256-307X/30/1/017601

摘要

As a potential building block for quantum information and computation,[1,2] single spin has attracted significant interest in the past decade.Various experimental techniques have been developed for single spin detection and control,such as nano-devices based on a single electron quantum dot,[3] magnetic resonance force microscopy,[4] spin-flip spectroscopy,[5] spin polarized scanning tunneling microscope (SP-STM),[6]and electron spin resonance scanning tunneling microscopy (ESR-STM).[7,8] Among these techniques,ESR-STM is unique for its potential ability in accessing spin coherence with the highest spatial resolution.In an ESR-STM,a paramagnetic spin undergoes Larmor precession in a magnetic field and induces a modulation in the tunneling current at a radio frequency,which can be detected with a preamplifier and a spectrum analyzer.Such a modulated signal has been observed in a few systems including defects on the semiconductor surface,[9,10] radicals of an adsorbed organic molecule,[11] and transition metal atoms.[12] However,the reported signal-to-noise (S/N) ratio up to date is mostly poor,and the underlying mechanism is still controversial.[13,14] Further investigations,especially the design of a novel experimental method for achieving a higher S/N ratio,is deeply deserved for the advancement of ESR-STM and the exploration of single spin dynamics.