org.soulspace.qclojure.adapter.backend.noisy-simulator — org.soulspace/qclojure 0.2.0

Advanced noisy quantum simulator backend implementing realistic quantum computing device simulation with comprehensive noise modeling.

This backend provides local simulation of quantum devices with noise using the domain layer's quantum state and circuit functionality. It serves as both a reference implementation and testing backend for quantum algorithms under realistic noise conditions.

This simulator models various types of quantum noise including:

• Depolarizing noise using Kraus operators
• Amplitude damping (T1 decay) modeling energy dissipation
• Phase damping (T2 dephasing) modeling pure dephasing
• Readout errors with configurable bit-flip probabilities
• Coherent errors and systematic rotation biases
• Gate-specific noise parameters based on real device calibration
• Comprehensive Amazon Braket quantum hardware noise models

The noise model can be configured with parameters such as T1 and T2 times, gate operation times, and noise strengths. It supports advanced noise configurations including correlated readout errors and coherent errors with specific rotation angles and axes. The simulator applies noise during gate operations and measurements, simulating realistic quantum device behavior.

The noise model map has the following structure:

{:gate-noise {
  :h {:noise-type :depolarizing :noise-strength 0.01}
  :x {:noise-type :amplitude-damping :noise-strength 0.02}
  :cnot {:noise-type :phase-damping :noise-strength 0.03}
  ...}
 :readout-error {:prob-0-to-1 0.05 :prob-1-to-0 0.02}}

Note: The simulator currently doesn't model crosstalk between qubits.

The simulator supports asynchronous job management, allowing users to submit circuits and retrieve results later. It can be used for testing algorithms, circuit designs, and quantum operations without requiring access to actual quantum hardware.

It also implements the CloudQuantumBackend protocol for mock cloud backend functionality, allowing it to be used in a cloud-like environment for testing purposes.

amplitude-damping-kraus-operators clj

(amplitude-damping-kraus-operators gamma)

Generate Kraus operators for amplitude damping (T1 decay).

Models energy dissipation where |1⟩ decays to |0⟩. Kraus operators: K₀ = [[1, 0], [0, √(1-γ)]], K₁ = [[0, √γ], [0, 0]]

Parameters:

• gamma: Damping parameter (0 <= gamma <= 1)

Returns: Vector of Kraus operators using fastmath complex numbers

apply-advanced-gate-noise clj

(apply-advanced-gate-noise state gate noise-config)

Apply advanced noise model during gate operation.

Parameters:

• state: Current quantum state
• gate: Gate operation
• noise-config: Advanced noise configuration

Returns: State after gate operation and noise

apply-advanced-readout-noise clj

(apply-advanced-readout-noise results readout-config)

Apply advanced readout noise with potential correlations.

Parameters:

• results: Clean measurement results
• readout-config: Advanced readout error configuration

Returns: Noisy measurement results

apply-depolarizing-noise clj

(apply-depolarizing-noise state qubit noise-prob)

Apply simple depolarizing noise to a quantum state.

apply-matrix-to-amplitude clj

(apply-matrix-to-amplitude amplitude-pair matrix)

Apply a 2x2 matrix to a single amplitude pair in a quantum state.

Performs proper complex matrix-vector multiplication: [new-a0] = [m00 m01] [a0] [new-a1] [m10 m11] [a1]

Parameters:

• amplitude-pair: [a0 a1] where each is a fastmath Vec2 complex number
• matrix: 2x2 matrix [[m00 m01] [m10 m11]] with fastmath complex elements

Returns: [new-a0 new-a1] as fastmath complex numbers

apply-quantum-channel clj

(apply-quantum-channel state kraus-operators qubit-index)

Apply a complete quantum channel defined by multiple Kraus operators.

For pure state simulators, implements quantum channels by randomly selecting one Kraus operator to apply with equal probability. This is a valid approximation for noise simulation.

Parameters:

• state: Input quantum state
• kraus-operators: Vector of Kraus operators with matrices
• qubit-index: Target qubit

Returns: Output quantum state after channel application

apply-readout-noise clj

(apply-readout-noise results prob-0-to-1 prob-1-to-0)

Apply readout error to measurement results.

apply-single-qubit-kraus-operator clj

(apply-single-qubit-kraus-operator state kraus-op qubit-index)

Apply a single Kraus operator to a specific qubit in a multi-qubit state.

This implements the proper quantum mechanics for Kraus operator application: |ψ'⟩ = K|ψ⟩ / ||K|ψ⟩||

The Kraus operator matrix should already include any coefficients.

Parameters:

• state: Quantum state
• kraus-op: Kraus operator {:matrix matrix}
• qubit-index: Target qubit (0-indexed)

Returns: New quantum state after applying Kraus operator and normalizing

atom-computing-noise clj

Noise model for Atom Computing neutral atom systems (future Amazon Braket).

Atom Computing characteristics:

• 100+ neutral atoms
• Reconfigurable architectures
• Long coherence times
• Potential for large-scale systems

calculate-decoherence-params clj

(calculate-decoherence-params t1 t2 gate-time)

Calculate decoherence parameters from T1, T2 times and gate duration.

Parameters:

• t1: T1 relaxation time (microseconds)
• t2: T2 dephasing time (microseconds)
• gate-time: Gate operation time (nanoseconds)

Returns: {:gamma-1 gamma-2} decoherence parameters

cleanup-noisy-completed-jobs! clj

(cleanup-noisy-completed-jobs!)

(cleanup-noisy-completed-jobs! max-age-ms)

Remove completed jobs older than specified time (in milliseconds).

Parameters:

• max-age-ms: Maximum age for completed jobs (default: 1 hour)

Returns: Number of jobs cleaned up

coherent-error-kraus-operator clj

(coherent-error-kraus-operator angle axis)

Generate Kraus operator for coherent (systematic) errors.

Parameters:

• angle: Rotation angle in radians
• axis: Rotation axis (:x, :y, or :z)

Returns: Single Kraus operator for coherent rotation

compare-hardware-platforms clj

(compare-hardware-platforms circuit platform-models)

Compare circuit fidelity across different quantum hardware platforms.

Parameters:

• circuit: Quantum circuit to analyze
• platform-models: Map of platform names to noise models

Returns: Map of platform comparisons with fidelity estimates and characteristics

create-advanced-noisy-simulator clj

(create-advanced-noisy-simulator noise-model)

(create-advanced-noisy-simulator noise-model config)

Create an advanced noisy quantum simulator with comprehensive noise modeling.

Parameters:

• noise-model: Advanced noise model configuration
• config: Optional simulator configuration

Returns: AdvancedNoisyQuantumSimulator instance

create-noisy-simulator clj

(create-noisy-simulator noise-model)

Create a simple noisy quantum simulator.

depolarizing-kraus-operators clj

(depolarizing-kraus-operators p)

Generate Kraus operators for depolarizing noise channel.

The depolarizing channel applies each Pauli operator with probability p/4, and leaves the state unchanged with probability 1-3p/4.

For proper normalization: Σᵢ Kᵢ† Kᵢ = I

Parameters:

• p: Total error probability (0 <= p <= 3/4 for physical channel)

Returns: Vector of Kraus operators with coefficients applied to matrices

estimate-circuit-fidelity clj

(estimate-circuit-fidelity circuit noise-model)

Estimate the overall fidelity of a circuit under given noise model.

This provides a rough estimate based on gate counts and noise strengths.

get-braket-noise-models clj

(get-braket-noise-models)

Get all available Amazon Braket quantum hardware noise models.

Returns: Map of device names to noise model configurations

get-noisy-simulator-stats clj

(get-noisy-simulator-stats)

Get statistics about the noisy simulator state.

Returns: Map with job counts and statistics

high-fidelity-superconducting clj

High-fidelity superconducting qubit noise model.

high-noise clj

ibm-brisbane-noise clj

Noise model for IBM Brisbane (superconducting) available on Amazon Braket.

IBM Brisbane characteristics:

• 127 qubits
• Falcon r5.11 processor
• Heavy-hex topology
• Advanced error suppression

ibm-kyoto-noise clj

Noise model for IBM Kyoto (superconducting) available on Amazon Braket.

IBM Kyoto characteristics:

• 127 qubits
• Condor r1 processor
• Enhanced error correction features
• Dynamic decoupling capabilities

ibm-lagos-noise clj

Noise model based on IBM Lagos quantum computer characteristics.

ibm-like-noise clj

ionq-aria-noise clj

Noise model for IonQ Aria (trapped ion) available on Amazon Braket.

IonQ Aria characteristics:

• 25 qubits (#AQ 20)
• Improved single-qubit gate fidelity (~99.9%)
• Improved two-qubit gate fidelity (~99.5%)
• Better connectivity and faster gates than Harmony

ionq-forte-noise clj

Noise model for IonQ Forte (trapped ion) available on Amazon Braket.

IonQ Forte characteristics:

• 32 qubits (#AQ 29)
• Latest generation with highest fidelity
• Enhanced error correction capabilities
• Fastest gate times in IonQ family

ionq-harmony-noise clj

Noise model for IonQ Harmony (trapped ion) available on Amazon Braket.

IonQ Harmony characteristics:

• 11 qubits
• Very high single-qubit gate fidelity (~99.8%)
• High two-qubit gate fidelity (~99.0-99.3%)
• Long coherence times
• Slower gate times due to laser operations

noisy-state clj

oxford-lucy-noise clj

Noise model for Oxford Quantum Computing Lucy (trapped ion) available on Amazon Braket.

Oxford Lucy characteristics:

• 8 qubits
• High-fidelity trapped ion qubits
• Competitive with IonQ systems
• Focus on networking and modular architectures

phase-damping-kraus-operators clj

(phase-damping-kraus-operators gamma)

Generate Kraus operators for phase damping (T2 dephasing).

Models random phase flips without energy loss. Kraus operators: K₀ = [[1, 0], [0, √(1-γ)]], K₁ = [[0, 0], [0, √γ]]

Parameters:

• gamma: Dephasing parameter (0 <= gamma <= 1)

Returns: Vector of Kraus operators using fastmath complex numbers

quera-aquila-noise clj

Noise model for QuEra Aquila (neutral atom) available on Amazon Braket.

QuEra Aquila characteristics:

• 256 neutral atoms
• Reconfigurable connectivity
• Rydberg blockade mechanism
• Unique noise sources from atom loading/transport

reset-noisy-simulator-state! clj

(reset-noisy-simulator-state!)

Reset the noisy simulator state, clearing all jobs and counters.

Returns: Updated state

rigetti-aspen-m3-noise clj

Noise model for Rigetti Aspen-M-3 (superconducting) available on Amazon Braket.

Rigetti Aspen-M-3 characteristics:

• 80 qubits
• Superconducting transmon qubits
• Fast gate times but shorter coherence
• Tunable coupling architecture

rigetti-aspen-noise clj

Noise model based on Rigetti Aspen quantum computer characteristics.

xanadu-x-series-noise clj

Noise model for Xanadu X-Series (photonic) available on Amazon Braket.

Xanadu X-Series characteristics:

• 216 modes (photonic qumodes)
• Continuous variable quantum computing
• Different noise characteristics from discrete systems
• Gate errors primarily from optical losses and thermal noise