Multi-terminal spin valve in a strong Rashba channel exhibiting three resistance states

Area of Science:

• Condensed Matter Physics
• Spintronics
• Quantum Materials

Background:

• Standard spintronic devices like spin valves and magnetic tunnel junctions exhibit two distinct resistance states.
• These states correspond to the parallel (P) and antiparallel (AP) alignment of ferromagnetic (FM) contacts.
• Strong spin-orbit interaction systems offer potential for novel electronic phenomena.

Purpose of the Study:

• To investigate the resistance states in a system with strong spin-orbit interaction.
• To explore the behavior of ferromagnetic contacts in conjunction with normal metal voltage probes.
• To determine if a three-resistance-state phenomenon can be observed and maintained.

Main Methods:

• Utilizing a quantum well layer exhibiting a strong Rashba effect.
• Employing two ferromagnetic (FM) contacts as current terminals.
• Using a separate normal metal contact pair as voltage terminals.

Main Results:

• Observation of three distinct resistance states: R_AP(1) > R_P > R_AP(2).
• The emergence of unequal antiparallel states, deviating from the conventional two-state behavior.
• Robustness of the three-state phenomenon up to room temperature.
• No degradation in the three-state observation with increased probe distances (up to 1.6 mm).

Conclusions:

• Strong spin-orbit interaction systems can host more than two resistance states.
• The observed unequal antiparallel states present a novel characteristic beyond standard spintronic devices.
• This phenomenon is stable and observable under practical conditions, including room temperature and extended probe distances.