SpectrumLookup Class¶
SpectrumLookup¶
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class
scqubits.core.spec_lookup.SpectrumLookup(framework, dressed_specdata, bare_specdata_list)[source]¶ The SpectrumLookup is an integral building block of the HilbertSpace and ParameterSweep classes. In both cases it provides a convenient way to translate back and forth between labelling of eigenstates and eigenenergies via the indices of the dressed spectrum j = 0, 1, 2, … on one hand, and the bare product-state labels of the form (0,0,0), (0,0,1), (0,1,0),… (here for the example of three subsys_list). The lookup table stored in a SpectrumLookup instance should be generated by calling <HilbertSpace>.generate_lookup() in the case of a HilbertSpace object. For ParameterSweep objects, the lookup table is generated automatically upon init, or manually via <ParameterSweep>.run().
- Parameters
framework (HilbertSpace or ParameterSweep) –
dressed_specdata (SpectrumData) – dressed spectral data needed for generating the lookup mapping
bare_specdata_list (SpectrumData) – bare spectral data needed for generating the lookup mapping
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bare_eigenenergies(subsys, param_index=0)[source]¶ Return list of bare eigenenergies for given subsystem.
- Parameters
subsys (QuantumSystem) – Hilbert space subsystem for which bare eigendata is to be looked up
param_index (int, optional) – position index of parameter value in question
- Returns
bare eigenenergies for the specified subsystem and the external parameter fixed to the value indicated by its index
- Return type
ndarray
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bare_eigenstates(subsys, param_index=0)[source]¶ Return ndarray of bare eigenstates for given subsystem and parameter index. Eigenstates are expressed in the basis internal to the subsystem.
- Parameters
subsys (QuantumSystem) –
param_index (int, optional) –
- Returns
- Return type
ndarray
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bare_index(dressed_index, param_index=0)[source]¶ For given dressed index, look up the corresponding bare index.
- Parameters
dressed_index (int) –
param_index (int) –
- Returns
Bare state specification in tuple form. Example: (1,0,3) means subsystem 1 is in bare state 1, subsystem 2 in bare state 0, and subsystem 3 in bare state 3.
- Return type
tuple of int
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bare_productstate(bare_index)[source]¶ Return the bare product state specified by bare_index.
- Parameters
bare_index (tuple of int) –
- Returns
ket in full Hilbert space
- Return type
qutip.Qobj
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classmethod
create_from_file(filename)¶ Read initdata and spectral data from file, and use those to create a new SpectrumData object.
- Parameters
filename (str) –
- Returns
new SpectrumData object, initialized with data read from file
- Return type
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classmethod
deserialize(io_data)¶ Take the given IOData and return an instance of the described class, initialized with the data stored in io_data.
- Parameters
io_data (scqubits.io_utils.file_io_base.IOData) –
- Returns
- Return type
Serializable
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dressed_eigenenergies(param_index=0)[source]¶ Return the array of dressed eigenenergies
- Parameters
param_index (int, optional) – position index of parameter value in question
- Returns
dressed eigenenergies for the external parameter fixed to the value indicated by the provided index
- Return type
ndarray
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dressed_eigenstates(param_index=0)[source]¶ Return the list of dressed eigenvectors
- Parameters
param_index (int, optional) – position index of parameter value in question, if called from within ParameterSweep
- Returns
dressed eigenvectors for the external parameter fixed to the value indicated by the provided index
- Return type
list of qutip.qobj eigenvectors
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dressed_index(bare_labels, param_index=0)[source]¶ For given bare product state return the corresponding dressed-state index.
- Parameters
bare_labels (tuple(int)) – bare_labels = (index, index2, …)
param_index (int, optional) – index of parameter value of interest
- Returns
dressed state index closest to the specified bare state
- Return type
int
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energy_bare_index(bare_tuple, param_index=0)[source]¶ Look up dressed energy most closely corresponding to the given bare-state labels
- Parameters
bare_tuple (tuple(int)) – bare state indices
param_index (int) – index specifying the position in the self.param_vals array
- Returns
dressed energy, if lookup successful
- Return type
float or None
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energy_dressed_index(dressed_index, param_index=0)[source]¶ Look up the dressed eigenenergy belonging to the given dressed index.
- Parameters
dressed_index (int) –
param_index (int) – relevant if used in the context of a ParameterSweep
- Returns
dressed energy
- Return type
float
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filewrite(filename)¶ Convenience method bound to the class. Simply accesses the write function.
- Parameters
filename (str) –
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get_initdata()¶ Returns dict appropriate for creating/initializing a new Serializable object.
- Returns
- Return type
dict
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serialize()¶ Convert the content of the current class instance into IOData format.
- Returns
- Return type
scqubits.io_utils.file_io_base.IOData