Many-fermion simulation from the contracted quantum eigensolver without fermionic encoding of the wave function

@article{Smart2022ManyfermionSF,
  title={Many-fermion simulation from the contracted quantum eigensolver without fermionic encoding of the wave function},
  author={Scott E. Smart and David A. Mazziotti},
  journal={Physical Review A},
  year={2022}
}
Quantum computers potentially have an exponential advantage over classical computers for the quantum simulation of many-fermion quantum systems. Nonetheless, fermions are more expensive to simulate than bosons due to the fermionic encoding—a mapping by which the qubits are encoded with fermion statistics. Here we generalize the contracted quantum eigensolver (CQE) to avoid fermionic encoding of the wave function. In contrast to the variational quantum eigensolver, the CQE solves for a many… 

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References

SHOWING 1-10 OF 70 REFERENCES

Quantum simulation of molecules without fermionic encoding of the wave function

Molecular simulations generally require fermionic encoding in which fermion statistics are encoded into the qubit representation of the wave function. Recent calculations suggest that fermionic

The Bravyi-Kitaev transformation for quantum computation of electronic structure.

An alternative method of simulating fermions with qubits, first proposed by Bravyi and Kitaev, is developed that reduces the simulation cost to O(log n) qubit operations for one fermionic operation and demonstrates the superior efficiency of the Bravyi-Kitaev method for all quantum computations of electronic structure.

Hardware-efficient variational quantum eigensolver for small molecules and quantum magnets

The experimental optimization of Hamiltonian problems with up to six qubits and more than one hundred Pauli terms is demonstrated, determining the ground-state energy for molecules of increasing size, up to BeH2.

Qubit Coupled Cluster Method: A Systematic Approach to Quantum Chemistry on a Quantum Computer.

A qubit coupled cluster (QCC) method that starts directly in the qubit space and uses energy response estimates for ranking the importance of individual entanglers for the variational energy minimization and provides an exact factorization of a unitary rotation of more than two qubits to a product of two-qubit unitary rotations.

Qubit-excitation-based adaptive variational quantum eigensolver

Molecular simulations with the variational quantum eigensolver (VQE) are a promising application for emerging noisy intermediate-scale quantum computers. Constructing accurate molecular ansätze that

Fermionic Quantum Computation

We define a model of quantum computation with local fermionic modes (LFMs)—sites which can be either empty or occupied by a fermion. With the standard correspondence between the Foch space of m LFMs

Qubit coupled cluster singles and doubles variational quantum eigensolver ansatz for electronic structure calculations

Variational quantum eigensolver (VQE) for electronic structure calculations is believed to be one major potential application of near term quantum computing. Among all proposed VQE algorithms, the

Strategies for quantum computing molecular energies using the unitary coupled cluster ansatz

The application of VQE to the simulation of molecular energies using the unitary coupled cluster (UCC) ansatz is studied and an analytical method to compute the energy gradient is proposed that reduces the sampling cost for gradient estimation by several orders of magnitude compared to numerical gradients.

Quantum-classical hybrid algorithm for the simulation of all-electron correlation.

A novel combination of quantum and classical algorithms, which computes the all-electron energy of a strongly correlated molecular system on the classical computer from the 2-Electron reduced density matrix (2-RDM) evaluated on the quantum device.

Quantum Solver of Contracted Eigenvalue Equations for Scalable Molecular Simulations on Quantum Computing Devices.

A quantum solver of contracted eigenvalue equations is introduced, the quantum analog of classical methods for the energies and reduced density matrices of ground and excited states and achieves an exponential speed-up over its classical counterpart.
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