Connecting physics to systems with modular spin-circuits

Abstract

An emerging paradigm in modern electronics is that of CMOS + $\mathsf{X}$ requiring the integration of standard CMOS technology with novel materials and technologies denoted by $\mathsf{X}$. In this context, a crucial challenge is to develop accurate circuit models for $\mathsf{X}$ that are compatible with standard models for CMOS-based circuits and systems. In this perspective, we present physics-based, experimentally benchmarked modular circuit models that can be used to evaluate a class of CMOS + $\mathsf{X}$ systems, where $\mathsf{X}$ denotes magnetic and spintronic materials and phenomena. This class of materials is particularly challenging because they go beyond conventional charge-based phenomena and involve the spin degree of freedom which involves non-trivial quantum effects. Starting from density matrices $-$ the central quantity in quantum transport $-$ using well-defined approximations, it is possible to obtain spin-circuits that generalize ordinary circuit theory to 4-component currents and voltages (1 for charge and 3 for spin). With step-by-step examples that progressively become more complex, we illustrate how the spin-circuit approach can be used to start from the physics of magnetism and spintronics to enable accurate system-level evaluations. We believe the core approach can be extended to include other quantum degrees of freedom like valley and pseudospins starting from corresponding density matrices.

References in corpus (28)

• The design and verification of Mumax3
• Thermally assisted magnetization reversal in the presence of a spin-transfer torque
• Non-collinear Magnetoelectronics
• Giant Spin Hall Effect Induced by Skew Scattering from Bismuth Impurities inside Thin Film CuBi Alloys
• Switching Distributions for Perpendicular Spin-Torque Devices within the Macrospin Approximation
• A full-stack view of probabilistic computing with p-bits: devices, architectures and algorithms
• CMOS + stochastic nanomagnets: heterogeneous computers for probabilistic inference and learning
• All Spin Logic device with inbuilt Non-Reciprocity
• Low Barrier Magnet Design for Efficient Hardware Binary Stochastic Neurons
• Persistent spin helix in Rashba-Dresselhaus two-dimensional electron systems
• Quantum World-line Monte Carlo Method with Non-binary Loops and Its Application
• Direct Observation of Valley Coupled Topological Current in MoS${}_2$
• Modular Compact Modeling of Magnetic Tunnel Junction Devices
• Double Free-Layer Magnetic Tunnel Junctions for Probabilistic Bits
• Voltage controlled spin precession
• Numerical Fokker-Planck study of stochastic write error slope in spin torque switching
• Transmission Line Model for Materials with Spin-Momentum Locking
• Double-Free-Layer Stochastic Magnetic Tunnel Junctions with Synthetic Antiferromagnets
• Voltage-insensitive stochastic magnetic tunnel junctions with double free layers
• Unified Framework for Charge-Spin Interconversion in Spin-Orbit Materials
• Physics-Based Models for Magneto-Electric Spin-Orbit Logic Circuits
• Valley-Coupled-Spintronic Non-Volatile Memories with Compute-In-Memory Support
• Heisenberg machines with programmable spin-circuits
• Equivalent Circuit for Magnetoelectric Read and Write Operations
• Spin circuit representation of spin pumping
• From Digital to Analogue Magnetoelectronics: Theory of Transport in Non-Collinear Magnetic Nanostructures
• Rectification in Spin-Orbit Materials Using Low Energy Barrier Magnets
• Non-Equilibrium Green's Function based Circuit Models for Coherent Spin Devices