Semiconductor Module Updates
For users of the Semiconductor Module, COMSOL Multiphysics® version 5.6 includes support for multicomponent wave functions and tensorial effective masses, new Lorentz Force and Rotating Frame features, and an improved drift-diffusion formulation for graded materials. Read more about these semiconductor features below.
Multicomponent Wave Function
The Schrodinger Equation interface has been expanded to support multicomponent wave functions and tensorial effective masses. With this new capability, there is a straightforward workflow for modeling multiband systems and particles with spins. You can see this functionality demonstrated in the k • p Method for Strained Wurtzite GaN Band Structure and A Silicon Quantum Dot in a Uniform Magnetic Field application examples.
Lorentz Force
This new feature adds the Lorentz force contribution to the kinetic momentum from the magnetic vector potential, useful for systems under the influence of magnetic fields. You can see this functionality demonstrated in the A Silicon Quantum Dot in a Uniform Magnetic Field application example.
Rotating Frame
The new Rotating Frame feature adds a contribution to the Hamiltonian corresponding to a rotating frame, making it easy to analyze systems in a rotating reference frame. You can see this functionality demonstrated in the Vortex Lattice Formation in a Rotating Bose–Einstein Condensate application example.
Wide Support for Eigenfrequency Analysis
The Eigenfrequency study is now supported for most of the AC/DC Module interfaces: Electric Currents, Electric Currents in Shells, Electric Currents in Layered Shells, Electrical Circuit, Electrostatics, and Magnetic Fields. In addition to supporting full-wave cavity mode analysis in the Magnetic Fields interface, it is possible to run eigenfrequency analyses with models involving electrical circuits. The eigenfrequency support is primarily developed for the AC/DC Module, but other modules that provide one of the affected physics interfaces will benefit from it too.
New and Enhanced Functionality for the Electrical Circuit Interface
For Time Dependent studies, the Electrical Circuit interface has been equipped with an "event-based" Switch feature. This allows you to model the "instantaneous" on-off switching of certain connections in the circuit. The switch can be current controlled, voltage controlled, or controlled by user-defined Boolean expressions.
Furthermore, Parameterized Subcircuit Definitions are added. Together with the Subcircuit Instance, these allow you to create your own building blocks containing smaller circuits, and use multiple parameterized variants of those in your larger circuit. Finally, the state, event, and solver machinery has been improved, especially the transient modeling of nonlinear (semiconductor) devices, which has become more robust.
The circuit improvements are primarily developed for the AC/DC Module, but other modules that provide access to the Electrical Circuit interface will benefit too. You can view the new functionality in these updated models:
- operational_amplifier_with_capacitive_load
- battery_over_-_discharge_protection_using_shunt_resistances
- p_-_n_diode_circuit
- reverse_recovery_of_a_pin_diode
Drift-Diffusion Formulation
The drift-diffusion formulation has been expanded for graded materials to include the effect of continuously varying effective density of states. (The quasi-Fermi level formulation already included this.)
New Tutorial Models
COMSOL Multiphysics® version 5.6 brings three new tutorial models to the Semiconductor Module.
k • p Method for Strained Wurtzite GaN Band Structure
Application Library Title:
k_dot_p_method_strained_wurtzite_gan_band_structure
Download from the Application Gallery
A Silicon Quantum Dot in a Uniform Magnetic Field
si_quantum_dot_in_uniform_magnetic_field
Download from the Application Gallery
Vortex Lattice Formation in a Rotating Bose-Einstein Condensate
vortex_lattice_formation_in_a_rotating_bose_einstein_condensate
Download from the Application Gallery