Session Z02: Mini-symposium: Quantum Sensors and Computing II

Synergistic efforts between Dark Matter and quantum computing using Qubits

Qubits are the building blocks of quantum computing. More recently, qubits have also demonstrated promising results as a possible dark matter detection technology that could reach the ultralight dark matter parameter space currently unreachable with existing technologies. This is due to qubits' single-photon resolution and sufficiently low dark count rates to observe the elusive dark matter signal. Therefore, the HEP community is finding applications of qubits in fundamental science more and more promising. Similarly, some of the challenges faced by the quantum computing community regarding the impact of cosmic and terrestrial radiation on qubits is the same problem the dark matter community has been working to mitigate for decades with their semiconductor devices. In this context, we will discuss how scientists from the dark matter and quantum computing communities are working together now to solve mutually relevant problems utilizing qubits as sensors.   

Frontiers in Quantum Simulation for Hight Energy Physics

Far from being static concepts familiar only from elementary quantum mechanics, the notions of quantum entanglement, entropy of entanglement, and decoherence are deeply relevant to processes at work in particle and nuclear systems. This fact, together with recent theoretical strides in formulating models for implementation on quantum devices, has led to an explosion of activity in quantum simulation aimed at particle physics. In addition to developing the underlying technology of quantum simulation, these efforts raise the exciting prospect of uncovering new understandings of structure and dynamics based on the entanglement and decoherence properties of simulated systems. In this talk, I survey the growing ecosystem of quantum simulation for particle physics while highlighting opportunities for NISQ-era computations and the insights into fundamental HEP they stand to provide.   

Quantum Simulation with Interacting Staggered Fermions

We are investigating different aspects of (1+1) dimensional staggered fermions with quantum computers. The model has a hopping term that connects neighboring sites and a SO(4) invariant four-fermion onsite interaction term. We are studying the time evolution of the theory and the structure of the ground state. The interest in the model stems from the fact that it is thought to be capable of generating a fermion mass without breaking symmetries. It is thought that this feature requires the ground state to have a highly entangled structure. Our model is free from sign problems and can hence be simulated using Monte Carlo methods. This allows us to test our quantum simulations.  We are also investigating the extension of the original model by adding a finite chemical potential to control the number of fermions. This enlarged model has a sign problem and thus can't be easily investigated with the classical simulation. We propose to implement a quantum simulation of this extended model. We are also investigating the model with tensor network renormalization.   

Quantum adiabatic machine learning with zooming (QAML-Z) on D-Wave Advantage Quantum Computer

QAML-Z is a quantum machine learning (QML) algorithm that categorizes high energy physics (HEP) events amongst a same-particle, different-topology background. In theory, QML utilizes the unique nature of quantum computers to perform faster than classical machine learning. However, in practice it's difficult to prove this quantum advantage, let alone physically implement it on a quantum computer; due mostly to the current, error-ful quantum computing (QC) hardware. In this presentation, we examine QAML-Z's performance on newly-updated QC hardware, and discuss the possibility of implementing quantum adiabatic correction (QAC) on QAML-Z.   

Perturbative boundaries of quantum advantage in lattice field theory

In a seminal paper on quantum computation of scattering amplitudes, Jordan, Lee and Preskill motivate their work by stating that perturbative series do not converge. 

However, when digitizations and truncations are introduced, this statement needs to be revisited. We show that finite harmonic digitizations lead to weak and strong coupling expansions

with finite radius of convergence for lambda phi four theories. We compare the computational resources needed. We also discuss converging perturbative methods used to describe 

analog simulators for the Abelian Higgs model based on configurable Rydberg atom arrays.    

Sub-MeV dark photon as dark matter in multi-temperature universe

Dark photon as dark matter is subject to several constraints such as it should have larger lifetime than the lifetime of the universe, satisfy the relic density limit, and be consistent with the BBN constraints. Here we discuss a sub-MeV dark photon model which survives these stringent constraints. The model includes two hidden sectors, one of which interacts directly with the visible sector while the second has only indirect coupling with the visible sector. Since the visible and the hidden sectors are in general in different bath temperatures, we use a formalism for the evolution of three bath temperatures: one for the visible sector and two for the hidden sectors and involves solution of Boltzmann equations coupling the three sectors. We will discuss the parameter region where the sub-MeV dark photon can exist and be consistent with all the current experimental constraints. Further, our analysis can be extended to a multi-temperature universe with multiple hidden sectors and multiple heat baths and may find application for a wider class of phenomena involving multiple sectors.

Based on:  JHEP 06 (2021) 086, arXiv: 2103.15769[hep-ph], by Amin Aboubrahim, Wan-Zhe Feng, Pran Nath, and Zhu-Yao Wang.