What is a quantum simulator?

  title={What is a quantum simulator?},
  author={Tomi H. Johnson and Stephen R. Clark and Dieter Jaksch},
  journal={EPJ Quantum Technology},
Quantum simulators are devices that actively use quantum effects to answer questions about model systems and, through them, real systems. In this review we expand on this definition by answering several fundamental questions about the nature and use of quantum simulators. Our answers address two important areas. First, the difference between an operation termed simulation and another termed computation. This distinction is related to the purpose of an operation, as well as our confidence in and… 
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The notion of AQS reliability is formalized by determining sensitivity of AQs outputs to underlying parameters, and conditions for robust simulation are formulated, which naturally reveals the importance of model symmetries in dictating the robust properties.
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Well-controlled quantum systems can potentially be used as quantum simulators. However, a quantum simulator is inevitably perturbed by coupling to additional degrees of freedom. This constitutes a
Quantum Chemistry Calculations on a Trapped-Ion Quantum Simulator
Quantum-classical hybrid algorithms are emerging as promising candidates for near-term practical applications of quantum information processors in a wide variety of fields ranging from chemistry to
Programming quantum computers using design automation
The challenges in fully-automatic quantum compilation are discussed and how to automatically perform the quantum programming flow from algorithm to a physical quantum computer for a simple algorithmic benchmark, namely the hidden shift problem is demonstrated.
Quantum Simulation of Non-Markovian Qubit Dynamics by an All-Optical Setup
We address the experimental implementation of a quantum simulator based on an optical setup. Our device can simulate the dynamical evolution of a qubit undergoing a dephasing process. In particular,
Effects of gate errors in digital quantum simulations of fermionic systems
Digital quantum simulations offer exciting perspectives for the study of fermionic systems such as molecules or lattice models. However, with quantum error correction still being out of reach with
Analyzing the spectral density of a perturbed analog quantum simulator using the Keldysh formalism
Simulation of interacting electron systems is one of the great challenges of modern quantum chemistry and solid state physics. Controllable quantum systems offer the opportunity to create artificial
Representation of Qubit States using 3D Memristance Spaces: A first step towards a Memristive Quantum Simulator
The results show that, at least in principle, qubits and one-qubit quantum gates can be simulated by memristor, and the first step towards the development of a new quantum simulator using memristors.
Harnessing the Power of the Second Quantum Revolution
The second quantum revolution has been built on a foundation of fundamental research at the intersection of physics and information science, giving rise to the discipline we now call Quantum


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The endeavour to control increasingly larger systems of particles at the quantum level is a natural goal, and will be a driving force for the physical sciences in the coming decades. The control of a
Adiabatic quantum simulators
In his famous 1981 talk, Feynman proposed that unlike classical computers, which would presumably experience an exponential slowdown when simulating quantum phenomena, a universal quantum simulator
Quantum analogue computing
  • V. Kendon, K. Nemoto, W. Munro
  • Computer Science, Physics
    Philosophical Transactions of the Royal Society A: Mathematical, Physical and Engineering Sciences
  • 2010
We briefly review what a quantum computer is, what it promises to do for us and why it is so hard to build one. Among the first applications anticipated to bear fruit is the quantum simulation of
Quantum Simulation
Simulating quantum mechanics is known to be a difficult computational problem, especially when dealing with large systems. However, this difficulty may be overcome by using some controllable quantum
Simulating chemistry using quantum computers.
This review discusses to what extent the ideas in quantum computation, now a well-established field, have been applied to chemical problems and describes algorithms that achieve significant advantages for the electronic-structure problem, the simulation of chemical dynamics, protein folding, and other tasks.
Can one trust quantum simulators?
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Universal Digital Quantum Simulation with Trapped Ions
The digital approach to quantum simulation in a system of trapped ions is demonstrated and evidence that the level of control required for a full-scale device is within reach is provided.
Digital quantum simulation of the statistical mechanics of a frustrated magnet.
A 'digital' quantum simulation of thermal states is reported; a three-spin frustrated magnet was simulated using a nuclear magnetic resonance quantum information processor, and the phase diagram of the system is explored at any simulated temperature and external field.
Quantum chemistry simulation on quantum computers: theories and experiments.
This paper presents a brief introduction to quantum chemistry evaluated via classical computers followed by typical procedures of quantum simulation towards quantum chemistry and predicts that in the near future quantum simulation will become a powerful tool for quantum chemistry over classical computations.
Digital Quantum Rabi and Dicke Models in Superconducting Circuits
All physical regimes, in particular those which are impossible to realize in typical cavity QED setups, can be simulated via unitary decomposition into digital steps through analog-digital quantum simulation using circuit quantum electrodynamics.