Difference between revisions of "Coherence.m"
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{{DISPLAYTITLE:coherence.m}} __NOTOC__ | {{DISPLAYTITLE:coherence.m}} __NOTOC__ | ||
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Coherence order selection function - keeps only the specified orders of coherence in the state vector. This function is useful as a replacement for gradients and phase cycles because coherence order filtering can be accomplished analytically, by just picking out the required coherence orders and zeroing everything else. | Coherence order selection function - keeps only the specified orders of coherence in the state vector. This function is useful as a replacement for gradients and phase cycles because coherence order filtering can be accomplished analytically, by just picking out the required coherence orders and zeroing everything else. | ||
==Syntax== | ==Syntax== | ||
| − | rho=coherence(spin_system,rho,spec) | + | rho=coherence(spin_system,rho,spec) |
==Arguments== | ==Arguments== | ||
| − | rho - a state vector or a horizontal stack thereof | + | rho - a state vector or a horizontal stack thereof |
spec - a cell array containing the specification of | spec - a cell array containing the specification of | ||
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==Outputs== | ==Outputs== | ||
| − | rho - the state vector with the undesired orders of | + | rho - the state vector with the undesired orders of |
spin correlations zeroed out | spin correlations zeroed out | ||
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==Examples== | ==Examples== | ||
| − | rho=coherence(spin_system,rho,{{'13C',[1 -1]},{'1H',-1}}); | + | rho=coherence(spin_system,rho,{{'13C',[1 -1]},{'1H',-1}}); |
keeps all states that simultaneously have coherence order 1 or -1 in the 13C subspace, and coherence order -1 in the 1H subspace. | keeps all states that simultaneously have coherence order 1 or -1 in the 13C subspace, and coherence order -1 in the 1H subspace. | ||
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==Notes== | ==Notes== | ||
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Because projection quantum number information is required, this function only works with ''sphten-liouv'' [[Basis set specification|formalism]]. It supports Fokker-Planck direct products. | Because projection quantum number information is required, this function only works with ''sphten-liouv'' [[Basis set specification|formalism]]. It supports Fokker-Planck direct products. | ||
==See also== | ==See also== | ||
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[[Kernel_functions#Coherence_order_selection|Coherence order selection]] | [[Kernel_functions#Coherence_order_selection|Coherence order selection]] | ||
Revision as of 15:48, 5 April 2026
Coherence order selection function - keeps only the specified orders of coherence in the state vector. This function is useful as a replacement for gradients and phase cycles because coherence order filtering can be accomplished analytically, by just picking out the required coherence orders and zeroing everything else.
Syntax
rho=coherence(spin_system,rho,spec)
Arguments
rho - a state vector or a horizontal stack thereof
spec - a cell array containing the specification of
which coherences to keep on which spins. For
example
{{'13C',[1 -1]},{'1H',-1}}
keeps the states that have coherence order
((1 OR -1 on 13C) AND (-1 on 1H))
Outputs
rho - the state vector with the undesired orders of
spin correlations zeroed out
Examples
rho=coherence(spin_system,rho,{{'13C',[1 -1]},{'1H',-1}});
keeps all states that simultaneously have coherence order 1 or -1 in the 13C subspace, and coherence order -1 in the 1H subspace.
rho=coherence(spin_system,rho,{{3,0},{5,-1}});
keeps all states that simultaneously have coherence order 0 on spin number 3, and coherence order -1 on spin number 5.
Notes
Because projection quantum number information is required, this function only works with sphten-liouv formalism. It supports Fokker-Planck direct products.
See also
State space indexing and manipulation
Version 2.8, authors: Ilya Kuprov, Luke Edwards
