Quantum state preparation and nonunitary evolution with diagonal operators
| Autor: | Anthony W. Schlimgen, Kade Head-Marsden, LeeAnn M. Sager-Smith, Prineha Narang, David A. Mazziotti |
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| Rok vydání: | 2022 |
| Předmět: |
Chemical Physics (physics.chem-ph)
Quantum Physics Mathematics::Operator Algebras TheoryofComputation_ANALYSISOFALGORITHMSANDPROBLEMCOMPLEXITY Physics - Chemical Physics MathematicsofComputing_NUMERICALANALYSIS FOS: Physical sciences Computational Physics (physics.comp-ph) Quantum Physics (quant-ph) Physics - Computational Physics |
| Zdroj: | Physical Review A. 106 |
| ISSN: | 2469-9934 2469-9926 |
| DOI: | 10.1103/physreva.106.022414 |
| Popis: | Realizing non-unitary transformations on unitary-gate based quantum devices is critically important for simulating a variety of physical problems including open quantum systems and subnormalized quantum states. We present a dilation based algorithm to simulate non-unitary operations using probabilistic quantum computing with only one ancilla qubit. We utilize the singular-value decomposition (SVD) to decompose any general quantum operator into a product of two unitary operators and a diagonal non-unitary operator, which we show can be implemented by a diagonal unitary operator in a 1-qubit dilated space. While dilation techniques increase the number of qubits in the calculation, and thus the gate complexity, our algorithm limits the operations required in the dilated space to a diagonal unitary operator, which has known circuit decompositions. We use this algorithm to prepare random sub-normalized two-level states on a quantum device with high fidelity. Furthermore, we present the accurate non-unitary dynamics of two-level open quantum systems in a dephasing channel and an amplitude damping channel computed on a quantum device. The algorithm presented will be most useful for implementing general non-unitary operations when the SVD can be readily computed, which is the case with most operators in the noisy intermediate-scale quantum computing era. |
| Databáze: | OpenAIRE |
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