Difference between revisions of "Isergen.m"

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m (Rename Arguments section heading to Parameters)
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==See also==
 
==See also==
[[Kernel_functions#Time_evolution|Time evolution functions]], [[step.m]], [[evolution.m]], [[krylov.m]]
+
[[step.m]], [[evolution.m]], [[krylov.m]], [[iserstep.m]], [[steady.m]], [[Kernel_functions]]
  
 
''Version 2.5, authors: [[Ilya Kuprov]], [[Andrew Graham]]''
 
''Version 2.5, authors: [[Ilya Kuprov]], [[Andrew Graham]]''

Latest revision as of 19:38, 6 June 2026

2nd and 4th order Iserles product quadrature generators for one time propagation step in the case of state-independent Hamiltonian.

Syntax

    H=isergen(HL,HM,HR,dt)

Parameters

    HL - Hamiltonian at the left edge of the interval

    HM - [optional] Hamiltonian at the interval mid-
         point; if this is empty, second order quad-
         rature is used.

    HR - Hamiltonian at the right edge of the interval

    dt - interval duration, seconds

Outputs

    H  - effective evolution generator, to be used
         as exp(-1i*H*dt)

Examples

Iserles product quadratures are vastly superior to the commonly used piecewise-constant Hamiltonian propagation routines. Below is the output of product_quadratures.m example file from examples/fundamentals directory.

Iserles.png

See also

step.m, evolution.m, krylov.m, iserstep.m, steady.m, Kernel_functions

Version 2.5, authors: Ilya Kuprov, Andrew Graham