Microelectronic Engineering 63 (2002) 211–216 www.elsevier.com / locate / mee Manifestation of Berry’s phase in Aharonov–Bohm oscillations in a 2D system with spin–orbit interaction * Jeng-Bang Yau , E.P. De Poortere, M. Shayegan Department of Electrical Engineering, Princeton University, Princeton, NJ 08544, USA Abstract Fourier spectra of the Aharonov–Bohm oscillations, measured in GaAs two-dimensional holes with a strong spin–orbit interaction, reveal side peaks in addition to the center peak whose frequency corresponds to the radius of the ring. A comparison of the experimental data with results of simulations demonstrates that the origin of the side peaks is the Berry’s phase.  2002 Elsevier Science B.V. All rights reserved. Keywords: Aharonov–Bohm oscillations; Berry’s phase; Spin–orbit interaction PACS: 72.15.R; 03.65.B; 71.70.Ej Since the introduction of the Aharonov–Bohm (AB) effect [1,2] in 1959, the phase factor that a quantum state acquires upon a cyclic evolution has been studied intensively. Berry [3] showed that, even in the absence of electromagnetic fields, when a quantum state undergoes an adiabatic evolution along a closed curve in parameter space, it develops a phase which depends only on this curve. To observe Berry’s phase in an electronic system with spin, Loss et al. [4] proposed to study transport in a mesoscopic ring structure in the presence of an orientationally inhomogeneous (e.g. radial) magnetic field. This can be experimentally implemented via fabricating the ring from a material with inversion asymmetry and spin–orbit (SO) interaction. In recent, pioneering studies [5,6], the AB oscillations were measured in an InAs two-dimensional (2D) electron system with strong SO interaction. A small splitting of the main peak in the averaged spectra of over 30 traces was interpreted as a possible manifestation of the Berry’s phase. Here we report AB measurements on a GaAs 2D hole system with well-characterized SO interaction [7]. The Fourier spectra of the AB oscillations contain well-resolved side peaks around the central peak which 2 occurs at pr /( h / e), where r is the ring radius. The position and strength of these side peaks evolve with the range of magnetic field over which the spectra are taken. Comparison of this evolution with *Corresponding author. Tel.: 11-609-258-5434; fax: 11-609-258-1840. E-mail address: tonyyau@ee.princeton.edu (J.B. Yau). 0167-9317 / 02 / $ – see front matter  2002 Elsevier Science B.V. All rights reserved. PII: S0167-9317(02)00605-6