DESY and Quantinuum: Breakthrough in Quantum Physics
A DESY Quantinuum collaboration looking at electric flus configurations in 2+1-dimensional Quantum Electrodynamics
The Quantum Computer
company Quantinuum and
the team of Karl Jansen, head of the Center for Quantum Technology and Applications (CQTA) at DESY, have been working
together
to tackle problems in the area of
"Lattice Gauge Theory", which is a mathematical formalism used to describe a broad
range of phenomena in High Energy Physics (HEP) and beyond.
The joint team made significant progress in approaching Lattice Gauge Theory corresponding to
Quantum Electrodynamics, the theory of light and matter.
For the first time, they were able to study
the full wavefunction of a two-dimensional confining system with gauge fields and dynamical
matter fields on a quantum processor. They were also able to visualize the confining string and
the string-breaking phenomenon at the level of the wavefunction, across a range of interaction strengths.
The team, comprising A. Crippa and K. Jansen from DESY and E. Rinaldi form Quantinuum,
approached the problem starting with the definition of the Hamiltonian using the InQuanto
software package of Quantinuum, and utilized the reusable protocols of InQuanto to compute
both projective measurements and expectation values. InQuanto allowed the easy integration of
measurement reduction techniques and scalable error mitigation techniques. Moreover, the
emulator and hardware experiments were orchestrated by the Quantinuum Nexus online platform.
In one section of the study, a circuit with 24 qubits and more than 250 two-qubit
gates was reduced to a smaller width of 15 qubits thanks our unique qubit re-use and
mid-circuit measurement automatic compilation implemented in TKET.
Quantum computing may be very well-suited to tackling problems in lattice gauge theory,
due to a quantum processor’s similar information density scaling – with the addition of
a single qubit to a QPU, the information the system contains doubles.
Quantinuum's 56-qubit System Model H2, for example, can hold quantum states that
require 128*(2^56) bits worth of information to describe (with double-precision numbers)
on a classical supercomputer, which is more information than the biggest supercomputer in the world can hold in memory.
The work paves the way towards using quantum computers to study lattice gauge theories
in higher dimensions, with the goal of one day simulating the full three-dimensional
Quantum Chromodynamics theory underlying the nuclear sector of the Standard Model of
particle physics. Being able to simulate full 3D quantum chromodynamics will undoubtedly
unlock many of Nature’s mysteries, from the Big Bang to the question
of CP-violation and the interior of neutron stars,
and is likely to lead to applications we haven’t yet dreamed of.
"The very fruitful and constructive collaboration with Quantinuum using their
quantum computer has offered us new insight in the confinement and string breaking
phenomena in an important Quantum Field Theory", says Jansen.
Someone of Quantinuum added " ".
There have been two other
papers coming from academic groups using quantum simulators, one using trapped ions and one
using neutral atoms. Another group, including scientists from Google, tackled
Lattice Gauge Theory using a superconducting quantum computer. Taken together, these papers
together with the DESY-Quantinuum one
indicate a growing interest in using quantum computing for High Energy Physics,
beyond simple one-dimensional systems which are more easily accessible with classical methods such as tensor networks.