IBM Quantum Computers Aid in Simulating Quantum Gravitational Fields, Researchers Achieve 90% Fidelity

Researchers from the Autonomous University of Madrid, University of Groningen, and University College London have successfully demonstrated the digital quantum simulation of gravitational optomechanics using IBM quantum computers. The team simulated the action of a Hamiltonian, which governs the interaction between a quantum mechanical oscillator and an optical field, generating quantum entanglement via gravitational effects. The process used a boson-qubit mapping protocol and a digital gate decomposition, achieving fidelities over 90%. This research could significantly advance our understanding of quantum physics and the universe, and holds promise for the future of digital quantum simulation.

What is the Digital Quantum Simulation of Gravitational Optomechanics?

The digital quantum simulation of gravitational optomechanics is a complex process that involves the use of IBM quantum computers. This process is spearheaded by a team of researchers from the Autonomous University of Madrid, University of Groningen, and University College London. The team has successfully showcased the digital quantum simulation of the action of a Hamiltonian, which governs the interaction between a quantum mechanical oscillator and an optical field. This interaction generates quantum entanglement between the two entities via gravitational effects.

The simulation process involves the use of a boson-qubit mapping protocol and a digital gate decomposition. These tools allow the researchers to run the simulations on the quantum computers available in the IBM Quantum platform. The results of the experiment are measured in terms of fidelity, with the achieved results corresponding to fidelities over 90%. This high fidelity indicates that entanglement was indeed generated through the simulation of a quantum gravitational field.

How Does the Quantum Simulation Process Work?

The quantum simulation process involves a novel approach to the open debate of quantum gravity. The focus of this approach is to prove the quantum nature of gravity without disclosing the underlying full quantum theory. The key aspect of this approach is the concept of entanglement. Since two quantum systems cannot be entangled via a classical channel if they were not entangled beforehand, the ability to show that the gravitational field is able to generate entanglement can lead to the conclusion that it must arise from genuine quantum properties. Therefore, the field must be a quantum entity.

The prospects for an experimental implementation of these proposals are encouraging. However, actual experimental results are still missing. In this context, a quantum simulation in a quantum computer could be helpful by informing the ongoing experimental efforts. This is made possible by leveraging the experimental amenability and tunability of modern quantum platforms.

What is the Role of IBM Quantum Computers in this Process?

IBM quantum computers play a crucial role in the digital quantum simulation of gravitational optomechanics. The researchers have applied a scheme to the high-fidelity digital quantum simulation of paradigmatic quantum-optics interactions such as beamsplitters or single-mode and two-mode squeezers. This scheme involves the use of a boson-qubit mapping to encode the Hamiltonian into a sequence of single-qubit and two-qubit gates.

The researchers have also reported the digital quantum simulation of the Hamiltonian involved in the generation of quantum entanglement between a pair of quantum harmonic oscillators by gravitational means. This work involves the application of this scheme to the digital quantum simulation in IBM quantum devices of the quantum gravitational Hamiltonian of gravitational optomechanics. This interaction gives rise to a bosonic two-mode Hamiltonian, which is translated into a multi-qubit one and then decomposed into one and two-qubit quantum gates in order to launch it to IBM quantum devices.

What are the Implications of this Research?

The implications of this research are significant. The preliminary four-qubit experiments are a first step towards larger quantum simulations with more modes and more photons per mode, beyond the capabilities of classical computers. The structure of the paper is the following: In the next section, the researchers introduce the Hamiltonian of gravitational optomechanics and develop its digitization. After that, they show how to realize a full quantum state tomography and compute the fidelity of this state with respect to theoretical predictions.

The researchers then present experimental results for the fidelity of the digital quantum simulation in IBM quantum computers. They conclude with a summary and discussion of their results. This research represents a significant step forward in the field of quantum physics and has the potential to revolutionize our understanding of the universe.

What is the Future of Digital Quantum Simulation?

The future of digital quantum simulation is promising. The researchers are interested in performing the digital quantum simulation of the interaction presented in the Hamiltonian of gravitational optomechanics. This interaction rules the interaction between a matter-wave and a photonic field mode. The interaction is governed by an optomechanical coupling whose value is related to the parameters of the experiment.

The researchers realized that this interaction is formally the same as the Hamiltonian interaction that arises in the field of optomechanics when studying a quantum system composed of a cavity field interacting with a movable mirror. This means that existing protocols from quantum optomechanics can be applied to this interaction. The researchers are optimistic about the potential of this research and are looking forward to further developments in the field of digital quantum simulation.