QubitizationCosts (Encodings) | Encodings

QubitizationCosts Type

Namespace: Encodings
Assembly: Encodings.dll
Parent Module: CostAnalysis
Base Type: obj
All Interfaces: IEquatable<QubitizationCosts> , IStructuralEquatable , IComparable<QubitizationCosts> , IComparable , IStructuralComparable

Qubitization resource estimate for a Hamiltonian expressed as an LCU.

In qubitization (quantum signal processing / quantum walk), the Hamiltonian is decomposed as H = Σₖ αₖ Uₖ where each Uₖ is unitary (a Pauli string). The key cost parameters are:

λ = Σ|αₖ| — the LCU 1-norm, governing query complexity
L = number of unitaries — governs ancilla width for SELECT/PREPARE
Query complexity: O(λ · t / ε) for time evolution to precision ε

Record fields

Record Field	Description
`DistinctUnitaries` Full Usage: `DistinctUnitaries` Field type: `int`	Number of distinct Pauli unitaries in the LCU decomposition. Field type: `int`
`Lambda` Full Usage: `Lambda` Field type: `float`	LCU 1-norm λ = Σ\|αₖ\|. Field type: `float`
`SelectAncillas` Full Usage: `SelectAncillas` Field type: `int`	Ancilla qubits for PREPARE/SELECT: ⌈log₂ L⌉. Field type: `int`
`SystemQubits` Full Usage: `SystemQubits` Field type: `int`	System (data) qubits. Field type: `int`
`TotalQubits` Full Usage: `TotalQubits` Field type: `int`	Total qubits: system + ancillas. Field type: `int`