Realizing gate control of spin-orbit coupling (SOC) is crucial for implementing semiconductor spintronic devices, with Rashba SOC being the key mechanism due to its electric-field sensitivity. GaN-based semiconductors are promising for room-temperature spintronics, owing to the availability of diluted magnetic semiconductors with Curie temperatures above room temperature. However, since Rashba SOC is inversely proportional to the band gap, effective electrical manipulation of SOC in wide band-gap GaN-based semiconductors has yet to be clearly established. In this study, we demonstrate that SOC can be effectively tuned by a front gate voltage by beating patterns of Shubnikov–de Haas SdH oscillations in AlGaN/GaN heterostructures. An anomalous gate-dependent decrease in the total SOC coefficient from $4.33\times {10}^{-12}\mathrm{eVm}$ (−6V) to $3.23\times {10}^{-12}\mathrm{eVm}$ (2V) (34% variation) in the two-dimensional electron gas is observed with the internal electric field increasing. This behavior is attributed to the enhancement of Rashba and Dresselhaus SOC with comparable magnitudes but opposite signs under gate control. This gate-tunable SOC provides an alternative platform for electrical control of spin precession in spin transistors. Furthermore, the ability to balance Rashba and Dresselhaus SOC strengths offers a route to prolong the spin lifetime and engineer the SU(2)-symmetric spin states in wurtzite heterostructures.

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• Dresselhaus coupling
• Spintronics
• III-V semiconductors
• Nitrides
• Shubnikov-de Haas effect