# Meetings

## 53rd Annual Meeting of the APS Division of Atomic, Molecular and Optical PhysicsMay 30 – June 3, 2022

### 7th Annual GPMFC Workshop on Exploring Physics With Quantum-Enabled Precision Measurement

Monday, May 30, 2022
8:50am–5:30pm

Workshop Fee: $150 ($75 for students)

IN-PERSON ONLY. You must also be registered for the full DAMOP Meeting in order to participate.

### Program

 8:50-9:00am WelcomeDavid Hanneke, Amherst College 9:00-9:30am An Introduction to Quantum Enhanced Sensing with Atoms and Photons Ivan Deutsch, University of New Mexico 9:30-10:00am Evidence of two-source King nonlinearity in spectroscopic fifth-force search in Yb+​ Diana Aude Craik, MITIsotope-shift spectroscopy has recently been put forward as a table-top method for searching for a hypothetical boson that mediates an interaction between the neutron and the electron. The Yukawa potential generated by this boson would lead to neutron-number-dependent shifts in atomic transition frequencies. When measured on at least two transitions, these shifts can be displayed in a “King plot”, which will exhibit nonlinearities in the presence of effects beyond the expected first-order standard model shifts. We have measured isotope shifts on three narrow optical transitions, on five spinless isotopes of Yb+. Our latest data, on the highly forbidden 467nm octupole transition between 2S1/2 and 2F7/2, when combined with our previous measurements of quadrupole transitions in Yb+ and recent measurements in neutral Yb, confirm the presence of a King nonlinearity with up 240σ confidence. The data also reveal, with 4.3σ sigma confidence, that this nonlinearity emerges from at least two distinct physical effects. We identify the main source of nonlinearity as differences in the 4th nuclear charge moment between isotopes, a higher-order nuclear effect that had not previously been probed with high precision. We find that the second source of nonlinearity likely cannot be explained by the expected next largest effect within the standard model, the quadratic field shift. We discuss possible sources for this second nonlinearity and outline how ongoing and future work can elucidate whether it emerges from a new boson. 10:00-10:30am JILA’s search for the electron’s electric dipole moment: a unique approach to searches for new physics Tanya Rousey, JILA/NISTWe are probing TeV-scale physics with a unique tabletop experiment which combines trapped molecular ions, rotating bias fields, orientation-resolved detection, and over a dozen lasers to both measure the electron’s electric dipole moment and constrain potential dark matter candidates. In this talk I will introduce the essence of our measurement as well as our methods for constraining both dark matter and parity-violating physics. 10:30-11:00am COFFEE BREAK 11:00-11:30am Quantum metrology enhanced by quantum error correction Sisi Zhou, CaltechRapid experimental progress has brought quantum metrology, the science of measurements and estimation in quantum systems, to the forefront of quantum science in the past decades. In this talk, I focus on the challenge of noise in quantum metrology from a quantum information perspective, and address the question of determining the ultimate estimation limits in quantum metrology under noise. In particular, we identify a simple criterion on general quantum systems that determines whether the Heisenberg limit in quantum metrology is achievable or not. We then explore quantum error correction as a powerful tool to achieve the ultimate estimation precision in both cases. Finally we present examples of quantum error-correcting codes for sensing in practical physical systems. 11:30am-12:00pm Optimal metrology with programmable quantum sensors Christian Marciniak, University of InnsbruckQuantum sensors are an established technology that has created new opportunities for precision sensing across the breadth of science. Using entanglement for quantum-enhancement will allow us to construct the next generation of sensors that can approach the fundamental limits of precision allowed by quantum physics. However, determining how state-of-the-art sensing platforms may be used to converge to these ultimate limits is an outstanding challenge. In this talk I will present our progress in this regard, where we merge concepts from the field of quantum information processing with metrology, and successfully implement experimentally a programmable quantum sensor operating close to the fundamental limits imposed by the laws of quantum mechanics. We achieve this by using low-depth, parametrized quantum circuits implementing optimal input states and measurement operators for a sensing task on a trapped ion experiment, particularly generalized Ramsey interferometery. We further perform on-device quantum-classical feedback optimization to `self-calibrate' the programmable quantum sensor. This ability illustrates that this next generation of quantum sensor can be employed without prior knowledge of the device or its noise environment. 12:00-12:30pm Quantum opto-mechanics and dark matter across disparate scales Daniel Carney, Berkeley National LabThe only things we know definitively about dark matter are roughly how much there is and that it gravitates. In particular, dark matter could have a wide range of possible masses and couplings. Quantum-limited mechanical sensors provide a robust platform to look for dark matter in many different regimes, and I will review the program of experiments emerging around this idea. After reviewing some current searches for certain light and medium-mass dark matter candidates, I will focus on the efforts of the Windchime collaboration, which aims to build an array of millions of optomechanical devices sensitive enough to search for heavy dark matter purely through its gravitational coupling. 12:30-2:00pm LUNCH (provided with registration) 2:00-2:30pm Control and detection of molecules in optical tweezers Lewis Picard, Harvard University Advances in quantum manipulation of molecules bring unique opportunities, including the use of molecules to search for new physics, harnessing molecular resources for quantum engineering, and exploring chemical reactions in the ultra-low temperature regime. Thus far, the coldest samples of neutral molecules have been prepared via association of ultracold atoms, with full quantum state control demonstrated in this system. The detection of these molecules is destructive, however, and relies on coherent transfer of molecules back to atoms. Inspired by work on detection of molecular ions via co-trapped atomic ions, I will discuss several approaches that we are pursuing utilizing messenger atoms (including atoms in Rydberg states) to realize the state-sensitive detection of neutral molecules. I will also discuss extending full state control to a reconfigurable 1-D tweezer array of 5 or more molecules. 2:30-3:00pm The HUNTER experiment: Searching for Sterile Neutrinos in laser trapped ^131Cs Paul Hamilton, UCLAThe HUNTER experiment (Heavy Unseen Neutrinos from Total Energy-momentum Reconstruction) is a search for sterile neutrinos with masses in the keV range.  Radioactive decays of laser-cooled 131-Cs will be reconstructed using reaction-microscope spectrometers to detect all charged decay products with high solid angle efficiency.  This reconstruction determines the mass of the undetected neutrino with keV-scale resolution and places limits on the coupling of a keV-scale sterile neutrino to SM neutrinos. 3:00-3:30pm Bounds on the bizarrity of the Universe from experiments with trapped, cold, charged particles Hartmut Haeffner, University of California, BerkeleyIn order to understand nature better, humans often had to expand their horizon with seemingly bizarre concepts. In the probably most targeted search for such new underlying concepts, theorists explore hypothetical concepts and make predictions which can be tested in controlled experiments. I will focus on two instances where high-precision control of trapped ions and electrons allows us to place bounds on such concepts. In the first, S. Weinberg was wondering whether the laws of nature at the quantum scale are nonlinear (Ann.Phys. (N.Y.), 194, 336-386 (1989)). However, no indications of nonlinearities could be detected even by using high precision spectroscopy. In addition, it became apparent that nonlinearities should lead to non causal effects and thus the idea of a nonlinear quantum theory became less attractive. However, recently Kaplan and Rajendran (arXiv:2106.10576 [hep-th]) managed to add non-linear and state-dependent terms without violating causality. Interestingly this extension rendered the existing experimental tests ineffective, mainly because the quantum mechanical test objects used to exclude nonlinearities were not localized. This delocalization leads to a dilution of the self-interaction between the superposition states of the wavefunction and hence the observable energy shift. I will discuss new experiments where the quantum mechanical object is tied to a macroscopic object (such as an ion trap) leading to sufficient localization such that a self-interaction could lead to measurable non-linearities. Secondly, I will turn my attention to another paradigm shift where modern quantum control over charged particles enables us to build particle detectors with very special properties. The general idea is to exploit the exquisite control of modern technology over trapped, cold, charged matter to detect even minute collisions (Carney et al., PRL 127 (6), 061804 (2021), Budker et al., arXiv:2108.05283 [hep-ph]). I will discuss how we may use this new class of detectors to search for dark matter candidates such as millicharge particles. 3:30-4:30pm COFFEE BREAK & POSTERS 4:30-5:00pm Simulating QCD with quantum tools? Zohreh Davoudi, University of MarylandThe strong force in nature, described by the quantum and relativistic framework of quantum chromodynamics (QCD), has long generated an active and growing field of research and discovery. In fact, despite its development over five decades ago, it still leaves us with many exciting questions to explore in the 21st century, with a multi-billion-dollar experimental investment that aims to understand the core of matter, and how matter interacts with candidates of new physics models, such as dark matter. While an extremely successful theoretical and computational program called lattice QCD has enabled a first-principles look into some properties of matter, we have yet to come up with a computationally more capable tool to predict the complex and surprising dynamics of matter from the underlying interactions. Can a large reliable (digital or analog) quantum simulator eventually enable us to study the strong force? What does a quantum simulator have to offer to simulate QCD and how far away are we from such a dream? In this talk, I will describe a vision for how we may go on a journey toward quantum simulating QCD, by motivating the need for novel theoretical, algorithmic, and hardware approaches to quantum-simulating this unique problem, and by providing examples of the early steps taken to date in establishing a quantum-computational lattice-QCD program. 5:00-5:30pm TBD Will Terrano, Arizona State University