CHANGELOG.md

Changelog

All notable changes to this project will be documented in this file.

The format is based on Keep a Changelog, and this project adheres to Semantic Versioning.

[1.0.0] - 2026-6-12

Added

• Added support for the Stabilizer formalism by introducing StabilizerState and QuantumManagerStabilizer
  • A new class QuantumManagerDenseQubit is added. It is the child class of QuantumManager and parent class of QuantumManagerKet and QuantumManagerDensity
  • Attributes truncation and dim are moved from the parent class QuantumManager to the child class QuantumManagerDensityFock; the Timeline.__init__() signature update: argument truncation is replaced with manager_kwargs
• Add a module to convert an arbitrary graph object to sequence configurations for QuantumRouter with MIM BSM
• Add FatTree topology and BCube topology
• Added the routing module: a new parent class RoutingProtocol for the subclasses StaticRoutingProtocol and DistributedRoutingProtocol. The register decorator is used to make it easy to plug in new routing protocols in the future.
• Add empty init() to Protocol to satisfy class hierarchy.
• Created project scripts for each config generator.
• Added the swapping module that has the following classes. The subclasses use the registry decorator (factory pattern).
  • Base class: EntanglementSwappingA & EntanglementSwappingB
  • Subclass for ket vector and density matrix: EntanglementSwappingA_Circuit & EntanglementSwappingB_Circuit
  • Subclass for Bell diagonal state: EntanglementSwappingA_BDS & EntanglementSwappingB_BDS
• Update the tutorial to catch up on the recent updates. Add notes saying refer to chapter 6 Application module for standard usage
• Introducing EARLY_EXPIRE message type. A request has a start_time and end_time. When a request is finished before the end_time, then the reservation (and the associated rules) should expire early. If not, the quantum network will keep generating entanglement pairs because the rules still exist.
• Added three minute tutorial (tutorial file, md, json file). Also reorganized nav bar to have about section, tutorial section, and moduale refrence

Changed

• Using typer for CLI, creates a unified interface for topology generation. Allow for custom graph objects in CLI.
• Moved all old topologies to NetworkX graph objects
• Docstring, documentation, comment, logging, and various cosmetic updates.
• Moved routing_protocol init() to network manager.
• Trigger empty inits for resource and network manager to enable future bootstrapping.
• Migrated utils/json_config_generators/ to sequence/config_generators/.
• Add a sender_delay argument to the Node.send_message() to account for processing delay, queueing delay, transmission delay, etc.
• Break down the quantum_manager.py into a module consisting of multiple files where each file has a quantum manager class
• Break down the quantum_state.py into a module consisting of multiple files where each file has a quantum state class

Removed

• Old configuration generators
• The old swapping.py is removed
• The old quantum_manager.py is removed
• The old quantum_state.py is removed
• Removed support for Python 3.11
• Removed qlan submodule

Fixed

• Some minor bugs in quantum states
• Fixed a bug in Node.send_qubit() where if there are no quantum channels available for the qubit to travel, a KeyError crash would occur.

[0.8.5] - 2026-2-27

Added

• NetworkManager ABC with a factory pattern for selection and future implementation of new network managers.
• File action_condition_set.py is added. This contains the action, condition, and request functions for entanglement generation, swapping, and purification.
• Class DistributedRoutingProtocol is added, among many other supporting classes in routing_distributed. This module does distributed entanglement routing.
• Class NetworkManager has two new attributes: forwarding_table and routing_protocol.
• Add a cutoff flag to memory to allow disable the expiration of memories.
• Add a template in config json for network manager to select routing protocols (distributed vs. static)
• Add seven new unit tests to cover the newly added routing_distributed module
• Added generate_reference_rst.py to generate the .rst files for the Read the Doc.

Changed

• RSVPProtocol is now decoupled from the DistributedNetworkManager.
• Moved ResourceReservationProtocol to RSVPProtocol in rsvp.py.
• Moved MemoryTimecard to memory_timecard.py and are instantiated by the NetworkManager
  • RSVPProtocol does not instantiate MemoryTimecard anymore. The timecards attribute in RSVPProtocol becomes a reference to the MemoryTimecard in NetworkManager
• NetworkManager is now DistributedNetworkManager
• Extend and refactor the tests in test_reservation.py
• Minor refactors pertaining to typing errors in memory.py, resource_manager.py, rule_manager.py, network_manager.py and reservation.py
• The create_rules() and load_rules() functions of the ResourceReservationProtocol were consolidated and moved to the ResourceManager generate_load_rules()
• The purification_mode class attribute is now part of a Reservation, and is contained within the message.
• Fixing typing issues with ResourceManagment, NetworkManager, ResourceReservationProtocol, and related functions throughout the codebase.
• Update the LICENSE.md copyright year
• The previous StaticRoutingProtocol class is split into two classes: StaticRoutingProtocol and ForwardingProtocol. This can be viewed as the separation of control-plane and the data plane for the entanglement routing module. The control plane does the routing, the data plane does the forwarding. The Routing Protocols write to the forwarding_table, while the Forwarding Protocol reads from the forwarding_table.
• Minor refactors in router_net_topo.py and network_manager.py.
• Memory.cutoff_ratio is allowed to be greater than 1.
• Suppress linear algebra-related warning (doing sqrtm on singular matrix)
• Tutorial Chapter 5 on Network Manager. A new figure for network manager is introduced.
• Read the Docs is updated. The remote Read the Docs can now pre-build the .rst files.
• Attribute protocol_type is moved from class EntanglementProtocol to class Protocol.

Removed

• Temporarily disabled setting the es_succ_prob and es_deg_rate from the RSVP protocol.
• routing.py module is removed, replaced by routing_distributed.py, routing_static.py, and forwarding.py.

[0.8.4] - 2025-12-14

Fixed

• A minor bug in tutorial two_node_eg.ipynb
• A minor bug in timeline.py

[0.8.3] - 2025-12-11

Added

• Add support for Python 3.14
• A new function read_version_from_pyproject(). Don't need to update the version number 0.x.x at multiple locations anymore

Changed

• Moves the build-backend from legacy python to uv. More speed, more verbose useful errors, no more specifying modules in pyproject, dependency locks

Fixed

• A minor bug in gui.py

[0.8.2] - 2025-11-21

Added

• A new state PURIFIED in MemoryInfo is introduced to enable the new purify strategy once, i.e. only purify one time. The previous existing stragety is renamed to until_target, i.e., keep purifing until reaching the target fidelity.
• QuantumManagerKet.get_ascending_keys(): call reorder_qubits_ascending_keys() before getting the state
• QuantumManagerKet.reorder_qubits_ascending_keys(): reorder the quantum state such that the corresponding keys are in ascending order.
• QuantumManagerDensity.get_ascending_keys() and QuantumManagerDensity.reorder_qubits_ascending_keys(): same reording qubits for density matrix formalism.
• quantum_utils.pretty_ket(): return a pretty-looking state vector string
• NetworkManager.get_reservation_protocol(): Method to get the resource reservation protocol in the network manager's protocol stack.

Changed

• Updated workflows development.yml, publish.yml, validation.yml. Only run on the main repository (sequence-toolbox/SeQUeNCe), preventing unintended builds and publishes from forks.
• Standardized gmpy2 context precision to 80 bits in timing-related modules (detector.py, optical_channel.py) for computation efficiency and sufficient accuracy.
• quantum_utils.measure_entangled_state_with_cache_ket(): make code more mathematically sound.
• A lot of minor refactoring (spacing, indentation, f-string, comments, docstring, etc.)
• Updated related pytest

Fixed

• Improved time calculations in Detector.record_detection to use high-precision gmpy2

Removed

• Remove all parallel module related stuff under utils/json_config_gnerators/*, config_generator.py and router_net_topo.py.
• Removing and reorganizing examples in the example folder.

[0.8.1] - 2025-09-17

Changed

• Migrate code to fit PEP requirements for py3.11

Fixed

• Fixed the Tutorial so it is compatible with SeQUeNCe version 0.8
• Add decoherence_error and validation for var in Memory.__init__

Removed

• Removed support for Python version 3.10

[0.8] - 2025-09-08

Added

• Class factory support for generation, purification
• Implements BDS formalism
• Implements single heralded entanglement generation protocol. See entanglement_management.generation.single_heralded

Changed

• Modified related code to account for the new factory pattern.
  • The generation-related modules are under entanglement_management.generation
  • The purification-related modules are under entanglement_management.purification
• Modified constants.py to include the new purification and generation protocols
• Change QuantumManager to use the internal factory pattern
  • The previous instance-level attribute formalism is changed into a class-level attribute _global_formalism
  • Class-level attribute _registry is used to register the subclasses of QuantumManager

Removed

• Removed the old generation and purification protocol classes
• Remove standalone factory class for quantum manager
• Most stuff introduced in v0.7.6 has been temporarily removed

[0.7.6] - 2025-8-29

Added

• Adds a configuration system to load plugins from external modules
• Implements dynamic import of EntanglementGeneration classes from specified plugins (Trajectree as the first example)
• Introduces a new ShellBSM component and truncation parameter support

[0.7.5] - 2025-8-28

Added

• Added method Node.get_component_by_name(), ResourceManager.expire_rules_by_reservation(), and kernel.quantum_utils.verify_same_state_vector()
• Added a new badge for monthly downloads from pepy.tech
• Added Caitao, Ansh, and Robert to the SeQUeNCe author list
• New pytest for the teleportation module.

Fixed

• Fixed TeleportApp and TeleportProtocol, a lot of redesigns, the major ones are:
  • Each TeleportApp has a list of TeleportProtocol instances, and each instances owns quantum memories
  • Fix timing issues in the TeleportApp: Let Bob first execute EntanglementGenerationA._entanglement_succeed(), then let Alice do the Bell measurement
  • Optimize the TeleportApp by expiring the rules and setting the comm memory to RAW right after the teleportation is done. Remove teleport_protocol from TeleportApp.teleport_protocols after its lifecycle is complete

Changed

• Rename QuantumNodeNetTopo to DQCNetTopo
• Updates to class DQCNode and TeleportMessage
• random_state() is moved from utils.random_state to kernel.quantum_utils
• Cosmetic updates, including doc strings

[0.7.4] - 2025-8-15

Added

• New class QuantumFactory that uses the Factory Method design pattern to manage creating various quantum state managers.
• New method NetworkManager.update_forwarding_table() to update the forwarding table in a quantum router.

Fixed

• Fixed a floating point issue in QuantumChannel.schedule_transmit() and QuantumChannel.transmit() caused by the float's precision limitations in Python. Package gmpy2 is used for high precision computation.
  • Version 0.7.3 attempted to fix this issue, but the fix was unsuccessful.
• In EntanglementGenerationA.received_message(), explicitly set the priority of the events for future start or update_memory to schedule_counter. It fixes an issue for the edge case when the BSM node is at the end nodes, i.e., distance to one end node is zero.

Changed

• Changed the delay in EntanglementGenerationA.received_message() to make it more efficient when the BSM node is not exactly at the middle of two end quantum routers.
• Rename QuantumNode to DQCNode, a node designed for distributed quantum computing.
• Some constants in module constants are changed from float to int.
• Several cosmetic updates.
• Some constants in module constants are moved back to module timeline.

Removed

• The badge for sequence monthly downloads is removed, because the website pypistats.org is down.

[0.7.3] - 2025-8-1

Added

• new class QuantumNode under topology.node. Adds QuantumNode class extending QuantumRouter with data memory and teleportation capabilities
• new class TeleportApp under app.teleport_app. Implements TeleportApp for managing quantum teleportation between nodes.
• new class Teleportation under entanglement_management.teleporation. Core teleportation protocol with Bell measurement and correction handling
• new class QuantumNodeTopo under topology.quantum_node_net_topo. Network topology class for quantum node networks
• new class Noise under utils.noise. Noise utilities for depolarizing and measurement error simulation
• The pytest for the above.

Fixed

• Fix a floating point issue in OpticalChannel.schedule_transmit().

Changed

• Minor update to README.md

[0.7.2] - 2025-4-28

Added

• New shields.io badges at for monthly downloads and python versions

Changed

• Updated requirements.txt
• Updated demo codes

[0.7.1] - 2025-4-25

Added

New Component Modules from this paper: https://arxiv.org/pdf/2411.11031.

• qlan.graph_gen
• qlan.correction
• qlan.measurement
• topology.qlan.client
• topology.qlan.orchestrator
• The unit tests in the folder tests/qlan
• Examples in the folder example/qlan.

New classes for classical nodes (no quantum attributes)

• kernel.entity.ClassicalEntity
• topology.node.ClassicalNode

Changed

• Updated the code and examples related to the quantum transducer introduced in version 0.7.0
• Minor bug fixes and cosmetic updates
• Add new publications to README.md

[0.7.0] - 2025-1-22

Added

New Component Modules from this paper: https://arxiv.org/pdf/2411.11377.

• Transducer
• Transmon
• FockDetector
• FockBeamSplitter2
• The unit tests in the folder tests
• Examples in the folder example/quantum_transduction.

Changed

• Reorganized the absorptive_memory related files
• Update the requirements.txt
• Update constants module
• Update comments here and there

[0.6.6] - 2024-12-17

Added

• Add support for Python 3.13
• Add support for the latest Numpy (2.2), SciPy (1.14), and QuTiP (5.0)

Changed

• Updated the demos of the tutorial for easy of understanding.
• Updated some comments, typing, arguments, and some other minor changes.
• Changelog updates:
  • Reversed the changelog, now the latest version update is at the top of the changelog, instead of previously at the bottom.
  • Added the timestamp for the version updates.

Removed

• Removed support for Python 3.9

[0.6.5] - 2024-11-20

Added

• Add new class BellDiagonalState for Bell Diagonal State.
• Add new Quantum Manager for Bell Diagonal State, i.e., QuantumManagerBellDiagonal.
• Add new class SingleHeralded BSM to support single heralded entanglement generation.
• Add support for time-dependent decoherence for the Bell Diagonal State in Memory class.

Changed

• Remove existing handlers in logging before setting the new handler

[0.6.4] - 2024-9-26

Changed

• Use Read the Docs for documentation. Update documentation. Old documentation website becomes obsolete.
• Update comments and README.md

Fixed

• Fix a bug in reservation protocol and routing protocol that may lead to route for src->dst being different than dst->src when the network has same length edges.

[0.6.3] - 2024-8-12

Added

• We have an Icon for SeQUeNCe!
• pip install sequence is now available!
• src folder is renamed to sequence
• Add sequence/constants.py to organize the common constants
• Add support for Python 3.12
• Add pyproject.toml

Changed

• Various refactoring, include but not limited to updating variable/method names, moving/deleting code, adding/rewriting comments, and making the code more succinct, etc.
• In README.md, installation with option --editable is encouraged.
• logging looks better
• In class Reservation, added attribute entanglement_number and id
• Update ResourceReservationProtocol.load_rules()
• Move utils/json_config_generators/generator_utils.py to sequence/utils/config_generator.py

Removed

• Removed support for Python 3.8
• Removed setup.py
• Removed MANIFEST.in

[0.6.2]

Added

• Moved around and added a few files in the examples folder
  • These are primarily for the IEEE QCE 2023 conference

Changed

• Modified the topology output of the GUI to be compatible with new topology upgrades
• Several bug fixes in the GUI

[0.6.1]

Added

• Added some groundwork for future topology upgrades

Changed

• made numerous bug fixes:
  • BSM and optical channel components received fixes
  • Some residual bugs with GUI usage have been fixed
  • Error with typing in Fock quantum manager has been fixed

Removed

• Removed support for scipy version 1.11. This is currently causing some issues with qutip.

[0.6.0]

Added

• Fock state density matrix encoding
• Quantum manager to use fock state density matrix
  • Add truncation attribute to quantum managers; Hilbert space dimension is truncation + 1
  • Supports error channels based on kraus operators and direct operator action on state
• Hardware models to use fock state density matrix
  • Absorptive quantum memory built on AFC
  • Interference and direct detection for state tomography

Changed

• Moved around and updated some error checking
• Temporarily removed mpich testing for python 3.8 and 3.9 (broken)

[0.5.4]

Added

• Added some additional error checking to individual quantum states
  • This includes additional error checking in the Photon class

Changed

• The entangle method for the Photon and FreeQuantumState classes has been changed to combine_state
• Updated chapter 1 tutorial in the documentation to match code example

Removed

• residual json5 references in examples

[0.5.3]

Changed

• Bug fixes to the GUI and QKD tests

[0.5.2]

Added

• Added more scripts for the QCE 2022 conference

Changed

• Fixed some bugs in the GUI code for classical communication delay

Removed

• Removed mpi4py from install instructions on the README

[0.5.1]

Changed

• Moved all parallel execution code to the parallel directory
  • Now installed as separate package psequence
  • New setup.py file and makefile specified in parallel folder
  • Minimum sequence requirement 0.5.1
• Parallel scripts are temporarily broken, will need to be rewritten for new structure

Removed

• Removed mpi4py and pytest-mpi requirements for main package

[0.5.0]

Added

• Tutorial materials for IEEE Quantum Week 2022 tutorial session

Changed

• Reworked interface for nodes and hardware elements
  • New Entity interface for receiving/passing photons
  • New method for nodes to handle incoming and outgoing qubits
  • Polished observer functionality
• Reworked some protocols to utilize new interface
• Some bug fixes for GUI

[0.4.0]

Added

• GUI for ease of simulation setup
• Framework for future GUI usage to run simulations
  • This feature is currently unimplemented and will not work
• Package dependencies for GUI (dash and plotly)

Changed

• Updated version requirement for numpy
  • This removes support for Python 3.7 and below
• Bug fixes to tutorial chapter 3
• Typo fixes to docstrings in reservation.py

[0.3.2]

Changed

• Corrected units in jupyter notebook example files
• Corrected units for the optical channel class
• Bug fixes for tutorial scripts

[0.3.1]

Added

• Mirror class for simple reflection of photons
  • Sends photon to another node with quantum channel connection to the local node
• Quantum++ package acknowledgement to README

[0.3.0]

Added

• parallel execution for the kernel module
• parallel directory with useful tools
  • Python and C++ servers for managing parallel kernel executions
  • Many examples for parallel execution
• updated documentation with parallel code
• utility files for generating network config JSON files

Changed

• Topology class has been made into a simplified base class
  • RouterNetTopo and QKDTopo classes added for specific network types
• tweaked library dependencies
  • added mpi4py and mpi-pytest requirements for parallel execution
  • removed json5 requirement

[0.2.4]

Added

• serialization of messages, circuits
• base classes for applications and quantum manager states
• photon loss method Photon.add_loss()

Changed

• moved all random number generation to network nodes
  • includes all components and quantum manager functions
  • utilizes Entity.get_generator() method
• reworked timeline events to handle cross-process events
  • most protocols and components now use strings instead of explicit instances for classes
• tweaked process of entangelement and reservation protocols
• EventList structure and interface with Timeline
• Timeline timing display

[0.2.3]

Added

• quantum state manager for quantum memories
• quantum circuit class (for use with quantum memories)
• qutip library dependency

Changed

• rewrite of quantum entanglement class
• change all optical channels to one-way

[0.2.2]

Added

• logging functionality with log module
• cached quantum state measurement

Changed

• changed all quantum state representations from list to tuple
• event removal system
• example scripts now use Timeline.seed() method
• Timeline event removal method

[0.2.1]

Added

• observer functionality for entities
• README file for documentation

Changed

• some method-level docstrings
• convert all component constructors from keyword to positional arguments
• change documentation directory from sphinx to docs

Removed

• push/pop functions for entities and non-stack protocols
• some unnecessary entity attributes