Difference between revisions of "Eigenfields.m"

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−
Hz  - field-dependent part of the laboratory-frame Hamiltonian operator
+
Hz  - field-dependent part of the laboratory-frame Hamiltonian operator
 
       in Hilbert space, or commutation superoperator in Liouville space,
 
       in Hilbert space, or commutation superoperator in Liouville space,
 
       normalised to 1 Tesla
 
       normalised to 1 Tesla
  
−
Hc  - field-independent part of the laboratory-frame Hamiltonian operator
+
Hc  - field-independent part of the laboratory-frame Hamiltonian operator
 
       in Hilbert space, or commutation superoperator in Liouville space,
 
       in Hilbert space, or commutation superoperator in Liouville space,
 
       containing couplings and offsets
 
       containing couplings and offsets
  
−
Hmw - observable operator in Hilbert space, or observable vector in
+
Hmw - observable operator in Hilbert space, or observable vector in
 
       Liouville space, without the amplitude prefactor
 
       Liouville space, without the amplitude prefactor
  
−
parameters.window      - magnetic-field window, Tesla
+
parameters.window      - magnetic-field window, Tesla
  
−
parameters.mw_freq    - microwave frequency, Hz
+
parameters.mw_freq    - microwave frequency, Hz
  
−
parameters.orientation - three Euler angles in radians specifying the
+
parameters.orientation - three Euler angles in radians specifying the
 
                         system orientation
 
                         system orientation
  
−
parameters.tm_tol      - relative transition moment tolerance
+
parameters.tm_tol      - relative transition moment tolerance
  
−
parameters.pp_tol      - peak position tolerance in Tesla; this should
+
parameters.pp_tol      - peak position tolerance in Tesla; this should
 
                         be much smaller than the typical line width
 
                         be much smaller than the typical line width
  
−
parameters.fwhm        - transition full width at half maximum, Tesla
+
parameters.fwhm        - transition full width at half maximum, Tesla
  
 
==Outputs==
 
==Outputs==
  
  
−
tran.tf - vector of transition fields in Tesla
+
tran.tf - vector of transition fields in Tesla
  
−
tran.tm - vector of transition moments
+
tran.tm - vector of transition moments
  
−
tran.tw - vector of transition FWHMs in Tesla
+
tran.tw - vector of transition FWHMs in Tesla
  
−
tran.pd - vector of energy level population differences
+
tran.pd - vector of energy level population differences
  
−
tran.ti - transition identity array, one row per transition
+
tran.ti - transition identity array, one row per transition
  
−
tran.tj - vector of scaled field-sweep Jacobians
+
tran.tj - vector of scaled field-sweep Jacobians
  
 
==Notes==
 
==Notes==

Revision as of 16:47, 5 June 2026

Computes resonance fields. For a Hamiltonian Hc+b*Hz, returns all magnetic fields b for which the difference between two eigenvalues of Hc+b*Hz is equal to the frequency provided, and the transition moment across the specified operator Hmw is significant.

Syntax

    tran=eigenfields(spin_system,parameters,Hz,Hc,Hmw)

Arguments

Hz  - field-dependent part of the laboratory-frame Hamiltonian operator
     in Hilbert space, or commutation superoperator in Liouville space,
     normalised to 1 Tesla
Hc  - field-independent part of the laboratory-frame Hamiltonian operator
     in Hilbert space, or commutation superoperator in Liouville space,
     containing couplings and offsets
Hmw - observable operator in Hilbert space, or observable vector in
     Liouville space, without the amplitude prefactor
parameters.window      - magnetic-field window, Tesla
parameters.mw_freq     - microwave frequency, Hz
parameters.orientation - three Euler angles in radians specifying the
                        system orientation
parameters.tm_tol      - relative transition moment tolerance
parameters.pp_tol      - peak position tolerance in Tesla; this should
                        be much smaller than the typical line width
parameters.fwhm        - transition full width at half maximum, Tesla

Outputs

tran.tf - vector of transition fields in Tesla
tran.tm - vector of transition moments
tran.tw - vector of transition FWHMs in Tesla
tran.pd - vector of energy level population differences
tran.ti - transition identity array, one row per transition
tran.tj - vector of scaled field-sweep Jacobians

Notes

In Hilbert space, the very efficient Schweiger-Stoll method is used. In Liouville space, the very general but rather slow generalised eigensolver supplied with Matlab is used.

See also

fieldsweep.m

Version 2.6, authors: Ilya Kuprov