Change Log

Version 2.1

Bug Fixes

  • Fixed a bug that overwrote <ParameterSweep>[“evals”] data with transition data when using plot_transitions().

  • Fixed proper integration of ParameterSweep into CentralDispatch, enabling proper warnings to the user when internal computed sweep data is out of sync with associated quantum system parameters.

  • Fixed a bug that could occur when a ParameterSweep was applied to a HilbertSpace object involving only a single subsystem.

Under the Hood

  • Enable use of weakref in CentralDispatch for proper garbage collection.

  • Extended pytests to basic CentralDispatch functionality

Version 2.0

Additions

  • New graphical user interface scqubits.GUI() illustrating single-qubit functionality of scqubits.

  • Introducing NamedSlotsNdarray as a convenient subclass of ndarray with name-based and value-based slicing, and immediate support for basic plots

  • Added functionality for extracting dispersive energy parameters (such as Kerr coupling strengths)

  • Improved support for transition plots (subsystem transitions, sidebands etc.)

  • Added Cos2PhiQubit class.

  • Added KerrOscillator class

  • Added GenericQubit (two-level system) so that toy models such as the Jaynes-Cummings model can be readily realized with HilbertSpace.

  • Added n and phi operators to the Oscillator class

  • Added helper methods convert_to_E_osc and convert_to_l_osc for Oscillator initialization

  • New and enhanced interface for defining interaction terms in HilbertSpace objects via .add_interaction()

  • Added option to input interaction as a Qobj, or specify interaction terms as string expressions; also represented in HilbertSpace.create() GUI

Improvements

  • Convergence for ZeroPi is now faster, thanks to a correction to the expression for the grid spacing in discretization.py.

  • Refactored ParameterSweep class, now allowing for multi-dimensional parameter sweeps

  • Added a warning describing total=True being the default in t1 calculations

Bug fixes

  • Fix to type conversion error affecting the number operator in operators.py

  • Rectified orientation of matrix2d plots to match axes labels

  • mode option for values displayed in matrix element plots was ignored

Internals

  • New support for higher-order stencils in discretized derivatives.

  • Improved formatting of __str__ methods (called when “printing” an scqubits class instance).

  • Under the hood: use of Python 3.6 compatible type annotations; unified formatting enabled by the black package

  • Improvements to fileIO speeding up operations (increased memore cache) and requiring less disk space (avoid literal redundancies in stored data).

Version 1.3.2

Bug fixes

  • bug fix: <qubit>.create() failed in jupyter notebooks due to missing image files

  • bug fix: corrected the form of the quasiparticle noise operator

Version 1.3.1

Major changes/additions

  • Coherence calculations for the majority of qubits. These allow for estimating coherence times and rates due to various noise channels.

  • A new units system: users can specify energy units of their system Hamiltonian. These units are automatically considered when plotting and in coherence time calculations.

  • Separated documentation and example jupyter notebooks into individual repositories, see scqubits-doc and scqubits-examples.

Minor changes/additions

  • Introduced tests for real-valuedness of zero-pi Hamiltonians (for speedup).

  • New options in plotting (e.g. grid).

Bug fixes

  • Fixed bug preventing the proper disabling of the progress bar.

  • Various bug fixes and improvements of file IO operations.

  • Fixed issue with color legend bar in .plot_matrixelements.

Version 1.2.3

  • Bug fix: the FullZeroPi Hamiltonian was incorrect in the case of nonzero dC.

  • improvement: thanks to adjusted ARPACK options, diagonalization should be noticeably faster for ZeroPi and FullZeroPi.

  • make pathos and dill the default for multiprocessing.

Version 1.2.2

  • Bug fix: implementation of the add_hc=True flag in InteractionTerm involved a bug that could lead to incorrect results

  • update to plotting routines now supports various extra plotting options such as linestyle=... etc.

  • added TunableTransmon class for flux-tunable transmon, including junction asymmetry

  • limit support to Python >= 3.6

  • corrections to documentation of FullZeroPi

  • added missing jupyter notebook illustrating use of HilbertSpace and ParameterSweep

  • overhaul of file IO system now allows saving and loading various scqubit data via a custom h5 file format

  • ipywidget support for creating qubits inside jupyter (try, for example, tmon = scqubits.Transmon.create())

Version 1.2.1

  • update to the setup script to properly include testing data with the PyPi release.

Version 1.2

Major changes/additions

  • scqubits now offers multiprocessing support for a number of methods.

  • Introduced checks ensuring that umbrella objects like HilbertSpace and ParameterSweep instances do not accidentally go “out-of-sync” with respect to their basic components. When needed, warnings are thrown for the user to re-run sweeps or spectrum lookups.

Under the hood:

  • Monitoring for changes of interdependent class instances is implemented through a central dispatch system. (disable: settings.DISPATCH_ENABLED)

  • Removed HilbertSpace reference from within InteractionTerm (throws deprecation warning if still used)

  • Made HilbertSpace inherit from tuple rather than list; composition changes to HilbertSpace warrant generating a new HilbertSpace instance

  • Shifted InteractionTerm.hamiltonian to HilbertSpace.interaction_hamiltonian

  • Created DataStore as general purpose parent class to SpectrumData

  • No longer store custom data inside ParameterSweep, sweep_generators.py functions return DataStore objects

Version 1.1.1

  • fixed a bug in display of FluxQubit wavefunction

  • internal refactoring

Version 1.1.0

  • new class InteractionTerm works in tandem with HilbertSpace to ease setup of composite systems with pairwise interactions

  • new ParameterSweep class efficiently generates spectral data for performing a scan of a HilbertSpace object over an external parameters

  • new Explorer class introduces interactive plots (see docs and demo ipynb)

  • cleaned up implementation of file Serializable operations

Version 1.0.0 (first release)