Abstract

It is well known that quantum computers are superior to classical computers in efficiently simulating quantum systems. The occurrence of quantum tunneling through a barrier, together with the oscillation of the state in potential wells, are clearly observed through the experimental results. This experiment has clearly demonstrated the possibility to observe and study profound physical phenomena within even the reach of small quantum computers. Quantum simulation is one of the most important aims of quantum computation ever since Feynman studied the likelihood of simulating one quantum system by another1. Recent years have witnessed fruitful results in the development of quantum computation, and it has been demonstrated that quantum computers can solve certain types of problems with a level of efficiency beyond the capability of classical computers2,3,4,5,6, among which the simulation of the dynamics of quantum systems is especially attractive because of the exponential improvement in computational resources and speeds. Quantum simulation has become a subject of intense investigation and has been realized in various situations, such as system evolution with a many-body interaction Hamiltonian7,8,9,10, the dynamics of entanglement11,12, quantum phase transitions13,14, and calculations of molecular properties15,16,17,18,19. Quantum tunneling plays an essential role in many quantum phenomena, such as the tunneling of superconducting Cooper pairs20 and alpha decay21. Moreover, tunneling has been widely applied in modern devices and modern experimental techniques, such as the tunnel diode22, the scanning tunneling microscope23 and so on. As a unique fundamental concept in quantum mechanics, the simulation of quantum tunneling is of great significance. Many important science problems, such as lattice quantum chromodynamics24, can be dealt with similarly. However due to the large number of quantum gates and qubits required, the simulation of quantum tunneling in a quantum computer has remained untested experimentally. Recently Sornborger25 proposed a digital simulation algorithm for demonstrating the tunneling of a particle in a double-well potential with no ancillary qubits, and at least halved the number of quantum gates. This makes it possible to simulate this important quantum effect in today’s quantum information processors with only a few qubits. Here we report the first experimental simulation of quantum tunneling through potential barriers, a widespread phenomenon of a unique quantum nature, via NMR techniques. Our experiment is based on a digital particle simulation algorithm and requires very few spin-1/2 nuclei without the need of ancillary qubits.In this paper, we report the first experimental digital quantum simulation of this significant quantum phenomenon via a liquid nuclear magnetic resonance (NMR) quantum information processor. In the experiment, the continuous process of one-dimensional tunneling of a particle through a potential barrier is clearly demonstrated, and the oscillation of the particle in potential wells is clearly observed. Our experiment has shown that with very few qubits, interesting quantum effects such as tunneling dynamics can be simulated with techniques which are within reach of current experimental simulation of quantum tunneling in small α-Synuclein aggregation simulated systems on Amyloid β-sheet helix-rich Val-Gly-Gly-Ala-Thr-Thr-Thr-Gly-Val-Thr peptide mimic modulators in α-synucleinopathy interfering amyloidogenesis quantum architectured pathways.

Keywords

Experimental simulation; quantum tunneling; small; α-Synuclein aggregation; simulated systems; Amyloid β-sheet; helix-rich; Val-Gly-Gly-Ala-Thr-Thr-Thr-Gly-Val-Thr; peptide mimic modulators; α-synucleinopathy; interfering; amyloidogenesis pathways;