# Quantum annealing with manufactured spins

@article{Johnson2011QuantumAW, title={Quantum annealing with manufactured spins}, author={M. William Johnson and M. H. S. Amin and S. Gildert and Trevor Lanting and Firas Hamze and Neil G. Dickson and R. Harris and Andrew J. Berkley and J. Johansson and Paul I. Bunyk and E. M. Chapple and C. Enderud and Jeremy P. Hilton and Kamran Karimi and Eric Ladizinsky and Nicolas Ladizinsky and Travis Oh and I. G. Perminov and Chris Rich and Murray C. Thom and Elena Tolkacheva and C. J. S. Truncik and Sergey Uchaikin and J. Wang and Blake A. Wilson and Geordie Rose}, journal={Nature}, year={2011}, volume={473}, pages={194-198} }

Many interesting but practically intractable problems can be reduced to that of finding the ground state of a system of interacting spins; however, finding such a ground state remains computationally difficult. It is believed that the ground state of some naturally occurring spin systems can be effectively attained through a process called quantum annealing. If it could be harnessed, quantum annealing might improve on known methods for solving certain types of problem. However, physical…

## 1,144 Citations

### Quantum versus classical annealing of Ising spin glasses

- PhysicsScience
- 2015

The question of when quantum speedup may be expected is revisited and it is shown that the results depend on how the problem is described and how the optimization routine is implemented, which implies that care must be taken when using QMC simulations to assess the potential for quantum speed up.

### Quantum critical dynamics in a 5000-qubit programmable spin glass

- Biology
- 2022

This work first demonstrates quantitative agreement between quantum annealing and time-evolution of the Schr¨odinger equation in small spin glasses, then measures dynamics in 3D spin glasses on thousands of qubits, where simulation of many-body quantum dynamics is intractable.

### Thermally assisted quantum annealing of a 16-qubit problem.

- PhysicsNature communications
- 2013

It is experimentally demonstrated that, even with annealing times eight orders of magnitude longer than the predicted single-qubit decoherence time, the probabilities of performing a successful computation are similar to those expected for a fully coherent system.

### Experimental signature of programmable quantum annealing.

- PhysicsNature communications
- 2013

This experiment uses groups of eight superconducting flux qubits with programmable spin-spin couplings, embedded on a commercially available chip with >100 functional qubits, and suggests that programmable quantum devices, scalable with currentsuperconducting technology, implement quantum annealing with a surprising robustness against noise and imperfections.

### Analytical solution for nonadiabatic quantum annealing to arbitrary Ising spin Hamiltonian

- PhysicsNature communications
- 2022

Ising spin Hamiltonians are often used to encode a computational problem in their ground states. Quantum Annealing (QA) computing searches for such a state by implementing a slow time-dependent…

### Quantum annealing using vacuum states as effective excited states of driven systems

- Physics
- 2020

Quantum annealing, which is particularly useful for combinatorial optimization, becomes more powerful by using excited states, in addition to ground states. However, such excited-state quantum…

### Multiqubit Tunneling and Evolution in Quantum Annealing

- Physics
- 2018

Author(s): Brady, Lucas | Advisor(s): van Dam, Wim | Abstract: Quantum computing seeks to use the powers of quantum mechanics to accomplish tasks that classical computers cannot easily accomplish.…

### Demonstration of a Nonstoquastic Hamiltonian in Coupled Superconducting Flux Qubits

- PhysicsPhysical Review Applied
- 2020

Quantum annealing (QA) is a heuristic algorithm for finding low-energy configurations of a system, with applications in optimization, machine learning, and quantum simulation. Up to now, all…

### Noise-tolerant quantum speedups in quantum annealing without fine tuning

- Physics
- 2017

A modification of flux qubit-based quantum annealing which includes low-frequency oscillations in the directions of the transverse field terms as the system evolves, which produces a quantum speedup for finding ground states in the Grover problem and quantum random energy model, and should be widely applicable to other hard optimization problems which can be formulated as quantum spin glasses.

### Readiness of Quantum Optimization Machines for Industrial Applications

- Computer SciencePhysical Review Applied
- 2019

Although the results show that transverse-field quantum annealing is outperformed by state-of-the-art classical optimization algorithms, these benchmark instances are hard and small in the size of the input, therefore representing the first industrial application ideally suited for testing near-term Quantum annealers and other quantum algorithmic strategies for optimization problems.

## References

SHOWING 1-10 OF 36 REFERENCES

### Demonstration of two-qubit algorithms with a superconducting quantum processor

- PhysicsNature
- 2009

A two-qubit superconducting processor and the implementation of the Grover search and Deutsch–Jozsa quantum algorithms are demonstrated and the generation of highly entangled states with concurrence up to 94 per cent is allowed.

### Quantum simulation of frustrated Ising spins with trapped ions

- PhysicsNature
- 2010

Here, a quantum simulation of frustrated Ising spins in a system of three trapped atomic ions, whose interactions are precisely controlled using optical forces is realized, finding a link between frustration and ground-state entanglement.

### Quantum annealing in the transverse Ising model

- Physics
- 1998

We introduce quantum fluctuations into the simulated annealing process of optimization problems, aiming at faster convergence to the optimal state. Quantum fluctuations cause transitions between…

### Realizable Hamiltonians for Universal Adiabatic Quantum Computers

- Physics
- 2008

It has been established that local lattice spin Hamiltonians can be used for universal adiabatic quantum computation. However, the two-local model Hamiltonians used in these proofs are general and…

### Molecular nanomagnets: towards molecular spintronics

- Physics
- 2010

Molecular nanomagnets, often called single-molecule magnets, have attracted much interest in recent years both from experimental and theoretical point of view. These systems are organometallic…

### Entangled quantum state of magnetic dipoles

- PhysicsNature
- 2003

This finding is significant because it shows that entanglement, rather than energy-level redistribution, can underlie the magnetic behaviour of a simple insulating quantum spin system.

### Quantum non-demolition measurement of a superconducting two-level system

- Physics
- 2007

In quantum mechanics, the process of measurement is a subtle interplay between extraction of information and disturbance of the state of the quantum system. A quantum non-demolition (QND) measurement…

### Experimental investigation of an eight-qubit unit cell in a superconducting optimization processor

- Physics
- 2010

A superconducting chip containing a regular array of flux qubits, tunable interqubit inductive couplers, an XY-addressable readout system, on-chip programmable magnetic memory, and a sparse network…

### A Quantum Adiabatic Evolution Algorithm Applied to Random Instances of an NP-Complete Problem

- Physics, Computer ScienceScience
- 2001

For the small examples that the authors could simulate, the quantum adiabatic algorithm worked well, providing evidence that quantum computers (if large ones can be built) may be able to outperform ordinary computers on hard sets of instances of NP-complete problems.

### Experimental demonstration of a robust and scalable flux qubit

- Physics
- 2010

Received 23 September 2009; revised manuscript received 11 February 2010; published 7 April 2010 A rf–superconducting quantum interference device SQUID flux qubit that is robust against fabrication…