arXiv subjects

Joseph Carlson

Publications and source records attributed to Joseph Carlson.

At least 19 recordsLinked to original sources

arXiv2026

Signal Processing Foundations of Reconfigurable Antennas in the Tri-Hybrid MIMO Architecture

To enable larger apertures in multipleinput multipleoutput MIMO systems the trihybrid MIMO architecture offers a promising lowcost and lowpower solution by introducing reconfigurable antennas as a third layer of precoding on top of conventional digital and analog processing In this paper we develop a unified signal processing framework for trihybrid MIMO that explicitly captures the electromagnetic EM characteristics of diverse reconfigurable antenna technologies We first propose a generic inputoutput model that incorporates the reconfigurable antenna layer into an effective channel representation revealing a fundamental coupling between the channel precoder and radiated power Building on this model we formulate a general optimization problem that jointly accounts for digital analog and antennadomain precoding under hardware and power constraints We then instantiate this framework across seven representative reconfigurable antenna architectures including parasitic arrays dynamic metasurface antennas fluidpixel antennas polarizationreconfigurable antennas stacked intelligent metasurfaces pinching antenna systems and nonradiating wires To systematically compare these heterogeneous architectures we introduce a new metric the reconfigurability efficiency factor REF which quantifies the performance gains achievable through antenna reconfiguration under realistic constraints Numerical results demonstrate the tradeoffs among aperture size power consumption hardware complexity and spectral efficiency Our results establish that EMlevel reconfiguration reshapes the signal processing design space highlighting the need for new architectures and algorithms that jointly optimize across digital analog and electromagnetic domains This work reveals that electromagnetic reconfiguration couples the channel and precoder

eess.SP↗

arXiv2026

Neutrino Flavor Evolution in High Flux Astrophysical Environments

We examine neutrino evolution in astrophysical environments where the neutrino flux is very large, including core-collapse supernovae and neutron star mergers. In these environments, the neutrino-neutrino and neutrino-antineutrino interactions are crucial. We include non-forward scattering of neutrinos and anti-neutrinos in a semi-classical treatment. Because of the large scale of neutrino momenta (2-10 MeV), the quantum evolution problem can be treated as a sum over incoherent paths in the and flavor of each neutrino. The phases between different neutrinos are essentially random because of the large kinetic terms. Momentum is conserved at each vertex, and important flavor symmetries are retained. Dynamics in the many-body neutrino system enable rapid equilibration in the energy and angular distributions of all flavors, and an equilibration of products of neutrino and anti-neutrino densities for each flavor at either large or zero background matter density. We also describe the evolution at moderate densities where the mass eigenstates differ for neutrinos and antineutrinos, and with time-varying background matter densities. The evolution maintains relevant symmetries and reduces to standard MSW oscillations in the appropriate limits. The rapid equilibration in energy and flavor can significantly impact energy deposition and nucleosynthesis in high-flux astrophysical environments, and potentially flavor energy relations in terrestrial supernovae neutrino observations.

hep-ph↗

arXiv2026

Evidence for Multimodal Superfluidity of Neutrons

We present theoretical and experimental evidence for a new phase of matter in neutron-rich systems that we call multimodal superfluidity. Using ab initio lattice calculations, we show that the condensate consists of coexisting s-wave pairs, p-wave pairs in entangled double pair combinations, and quartets composed of bound states of two s-wave pairs. We identify multimodal superfluidity as a general feature of single-flavor spin-1/2 fermionic systems with attractive s-wave and p-wave interactions, provided the system is stable against collapse into a dense droplet. Beyond neutrons at sub-saturation densities, we demonstrate that this phase appears in generalized attractive extended Hubbard models in one, two, and three dimensions. We elucidate the mechanism for this coexistence using self-consistent few-body Cooper models and compare with Bardeen-Cooper-Schrieffer theory. We also derive the form of the effective action and show that spin, rotational, and parity symmetries remain unbroken. Finally, we analyze experimental data to show that p-wave pair gaps and quartet gaps are present in atomic nuclei, and we discuss the consequences of this new phase for the structure and dynamics of neutron star crusts.

nucl-th↗

arXiv2025

State preparation and symmetries

We demonstrate the importance of symmetries in Variational Quantum Eigensolver (VQE) algorithms to prepare the ground or specific low-lying states of quantum Hamiltonians. We examine two spin problems, one with random all-to-all couplings inspired by neutrino flavor evolution in supernovae, and the standard Heisenberg spin Hamiltonian on a $4 \times 3$ lattice. The neutrino Hamiltonian has the total spin $J$ and third component $J_{\rm{z}}$ as its only symmetries. The Heisenberg model has these symmetries plus translational invariance and reflection symmetry. We demonstrate that the convergence of variational methods is dramatically improved by keeping all symmetries. In both cases a nearly exact solution can be obtained in cases where standard unconstrained variational algorithms fail. Since variational algorithms can use standard Trotter steps as part of the optimization, allowing additional correlations that obey all the symmetries of the Hamiltonian will speed convergence of variational algorithms. This will lead to faster convergence than standard projection algorithms.

quant-ph↗

arXiv2025

Quantum Monte Carlo calculation of $\delta_{\rm NS}$ in $^{10}$C using an effective field theory approach

We compute radiative corrections to the superallowed $\beta$ decay of $^{10}{\rm C}$ in an effective field theory approach using nuclear matrix elements obtained from quantum Monte Carlo calculations. These corrections are an important ingredient in the extraction of the Cabibbo-Kobayashi-Masakawa quark mixing matrix element $V_{ud}$, and the role of this work is to illuminate the uncertainties arising from nuclear structure. Our results provide good agreement with both the traditional extraction of $V_{ud}$, as well as with a more recent evaluation performed using the no-core shell model and a dispersion formalism. The dominant uncertainty in this approach is the presence of two unknown low-energy constants that enter into the relevant nuclear matrix elements. Future determinations of these low-energy constants -- either from QCD or modeling them with two nucleon amplitudes -- would improve the precision of the extraction in this formalism.

nucl-th↗

arXiv2025

The Tri-Hybrid MIMO Architecture

We present an evolution of multiple-input multiple-output (MIMO) wireless communications known as the tri-hybrid MIMO architecture. In this framework, the traditional operations of linear precoding at the transmitter are distributed across digital beamforming, analog beamforming, and reconfigurable antennas. Compared with the hybrid MIMO architecture, which combines digital and analog beamforming, the tri-hybrid approach introduces a third layer of electromagnetic beamforming through antenna reconfigurability. This added layer offers a pathway to scale MIMO spatial dimensions, important for 6G systems operating in centimeter-wave bands, where the tension between larger bandwidths and infrastructure reuse necessitates ultra-large antenna arrays. We introduce the key features of the tri-hybrid architecture by (i)~reviewing the benefits and challenges of communicating with reconfigurable antennas, (ii)~examining tradeoffs between spectral and energy efficiency enabled by reconfigurability, and (iii)~exploring configuration challenges across the three layers. Overall, the tri-hybrid MIMO architecture offers a new approach for integrating emerging antenna technologies in the MIMO precoding framework.

cs.IT↗

arXiv2024

Frequency-selective beamforming and single-shot beam training with dynamic metasurface antennas

Dynamic metasurface antennas (DMAs) beamform through low-powered components that enable reconfiguration of each radiating element. Previous research on a single-user multiple-input-single-output (MISO) system with a dynamic metasurface antenna at the transmitter has focused on maximizing the beamforming gain at a fixed operating frequency. The DMA, however, has a frequency-selective response that leads to magnitude degradation for frequencies away from the resonant frequency of each element. This causes reduction in beamforming gain if the DMA only operates at a fixed frequency. We exploit the frequency reconfigurability of the DMA to dynamically optimize both the operating frequency and the element configuration, maximizing the beamforming gain. We leverage this approach to develop a single-shot beam training procedure using a DMA sub-array architecture that estimates the receiver's angular direction with a single OFDM pilot signal. We evaluate the beamforming gain performance of the DMA array using the receiver's angular direction estimate obtained from beam training. Our results show that it is sufficient to use a limited number of resonant frequency states to do both beam training and beamforming instead of using an infinite resolution DMA beamformer.

eess.SP↗

arXiv2024

Simplified projection on total spin zero for state preparation on quantum computers

We introduce a simple algorithm for projecting on $J=0$ states of a many-body system by performing a series of rotations to remove states with angular momentum projections greater than zero. Existing methods rely on unitary evolution with the two-body operator $J^2$, which when expressed in the computational basis contains many complicated Pauli strings requiring Trotterization and leading to very deep quantum circuits. Our approach performs the necessary projections using the one-body operators $J_x$ and $J_z$. By leveraging the method of Cartan decomposition, the unitary transformations that perform the projection can be parameterized as a product of a small number of two-qubit rotations, with angles determined by an efficient classical optimization. Given the reduced complexity in terms of gates, this approach can be used to prepare approximate ground states of even-even nuclei by projecting onto the $J=0$ component of deformed Hartree-Fock states. We estimate the resource requirements in terms of the universal gate set {$H$,$S$,CNOT,$T$} and briefly discuss a variant of the algorithm that projects onto $J=1/2$ states of a system with an odd number of fermions.

quant-ph↗

arXiv2024

Quantum Monte Carlo calculations of electron scattering from $^{12}\text{C}$ in the Short-Time Approximation

The Short-Time approximation is a method introduced to evaluate electroweak nuclear response for systems with $A\geq12$, extending the reach of first-principle many-body Quantum Monte Carlo calculations. Using realistic two- and three-body nuclear interactions and consistent one- and two-body electromagnetic currents, we calculate longitudinal and transverse response densities and response functions of $^{12}\text{C}$. We compare the resulting cross sections with experimental data for electron-nucleus scattering, finding good agreement.

nucl-th↗

arXiv2024

Solving reaction dynamics with quantum computing algorithms

The description of quantum many-body dynamics is extremely challenging on classical computers, as it can involve many degrees of freedom. On the other hand, the time evolution of quantum states is a natural application for quantum computers that are designed to efficiently perform unitary transformations. In this paper, we study quantum algorithms for response functions, relevant for describing different reactions governed by linear response. We focus on nuclear-physics applications and consider a qubit-efficient mapping on the lattice, which can efficiently represent the large volumes required for realistic scattering simulations. For the case of a contact interaction, we develop an algorithm for time evolution based on the Trotter approximation that scales logarithmically with the lattice size, and is combined with quantum phase estimation. We eventually focus on the nuclear two-body system and a typical response function relevant for electron scattering as an example. We also investigate ground-state preparation and examine the total circuit depth required for a realistic calculation and the hardware noise level required to interpret the signal.

quant-ph↗

arXiv2023

Hierarchical Codebook Design with Dynamic Metasurface Antennas for Energy-Efficient Arrays

Dynamic metasurface antennas (DMA) provide a solution to form compact, cost-effective, energy-efficient multiple-input-multiple output (MIMO) arrays. In this paper, we implement a practical hierarchical codebook with a realistic DMA design through electromagnetic simulations. We leverage existing DMA models to derive a novel method for enhancing the beamforming gain. We find that the proposed method provides better coverage and spectral efficiency results than prior methods. We also present and verify a new technique for creating wide beamwidths through the DMA and hierarchical codebook. Additionally, we use a detailed transmitter architecture model to determine the power consumption savings of the DMA compared to a typical phased array. The DMA largely outperforms a passive phased array in terms of spectral and energy efficiency due to high component loss from a high-resolution passive phase shifter. While the DMA provides lower spectral efficiency results than the active phased array, the DMA achieves a higher energy efficiency because of the significant power consumption for the active phase shifters. Therefore, we find that DMAs in a realistic wireless environment provide sufficient coverage and spectral efficiency compared to typical phased arrays while maintaining a substantially lower power consumption.

eess.SP↗

arXiv2023

Quantum Information Science and Technology for Nuclear Physics. Input into U.S. Long-Range Planning, 2023

In preparation for the 2023 NSAC Long Range Plan (LRP), members of the Nuclear Science community gathered to discuss the current state of, and plans for further leveraging opportunities in, QIST in NP research at the Quantum Information Science for U.S. Nuclear Physics Long Range Planning workshop, held in Santa Fe, New Mexico on January 31 - February 1, 2023. The workshop included 45 in-person participants and 53 remote attendees. The outcome of the workshop identified strategic plans and requirements for the next 5-10 years to advance quantum sensing and quantum simulations within NP, and to develop a diverse quantum-ready workforce. The plans include resolutions endorsed by the participants to address the compelling scientific opportunities at the intersections of NP and QIST. These endorsements are aligned with similar affirmations by the LRP Computational Nuclear Physics and AI/ML Workshop, the Nuclear Structure, Reactions, and Astrophysics LRP Town Hall, and the Fundamental Symmetries, Neutrons, and Neutrinos LRP Town Hall communities.

nucl-ex↗

arXiv2021

Nuclear two point correlation functions on a quantum-computer

The calculation of dynamic response functions is expected to be an early application benefiting from rapidly developing quantum hardware resources. The ability to calculate real-time quantities of strongly-correlated quantum systems is one of the most exciting applications that can easily reach beyond the capabilities of traditional classical hardware. Response functions of fermionic systems at moderate momenta and energies corresponding roughly to the Fermi energy of the system are a potential early application because the relevant operators are nearly local and the energies can be resolved in moderately short real time, reducing the spatial resolution and gate depth required. This is particularly the case in quasielastic electron and neutrino scattering from nuclei, a topic of great interest in the nuclear and particle physics communities and directly related to experiments designed to probe neutrino properties. In this work we use current quantum hardware and error mitigation protocols to calculate response functions for a highly simplified nuclear model through calculations of a 2-point real time correlation function for a modified Fermi-Hubbard model in two dimensions with three distinguishable nucleons on four lattice sites.

quant-ph↗

arXiv2021

Electron scattering on ${\mathbf{A=3}}$ nuclei from quantum Monte Carlo based approaches

We perform first-principle calculations of electron-nucleus scattering on $^3$He and $^3$H using the Green's function Monte Carlo method and two approaches based on the factorization of the final hadronic state: the spectral-function formalism and the short-time approximation. These three methods are benchmarked among each other and compared to the experimental data for the longitudinal and transverse electromagnetic response functions of $^3$He, and the inclusive cross sections of both $^3$He and $^3$H. Since these three approaches are based on the same description of nuclear dynamics of the initial target state, comparing their results enables a precise quantification of the uncertainties inherent to factorization schemes. At sufficiently large values of the momentum transfer, we find an excellent agreement of the Green's function Monte Carlo calculation with experimental data and with both the spectral-function formalism and the short-time approximation. We also analyze the relevance of relativistic effects, whose inclusion becomes crucial to explain data at high momentum and energy transfer.

nucl-th↗

arXiv2021

Simulation of Collective Neutrino Oscillations on a Quantum Computer

In astrophysical scenarios with large neutrino density, like supernovae and the early universe, the presence of neutrino-neutrino interactions can give rise to collective flavor oscillations in the out-of-equilibrium collective dynamics of a neutrino cloud. The role of quantum correlations in these phenomena is not yet well understood, in large part due to complications in solving for the real-time evolution of the strongly coupled many-body system. Future fault-tolerant quantum computers hold the promise to overcome much of these limitations and provide direct access to the correlated neutrino dynamic. In this work, we present the first simulation of a small system of interacting neutrinos using current generation quantum devices. We introduce a strategy to overcome limitations in the natural connectivity of the qubits and use it to track the evolution of entanglement in real-time. The results show the critical importance of error-mitigation techniques to extract meaningful results for entanglement measures using noisy, near term, quantum devices.

quant-ph↗

arXiv2021

Quasielastic Electromagnetic Scattering Cross Sections and World Data Comparisons in the {\fontfamily{qcr}\selectfont GENIE} Monte Carlo Event Generator

The usage of Monte Carlo neutrino event generators (MC$ν$EGs) is a norm within the high-energy $ν$ scattering community. The relevance of quasielastic (QE) energy regimes to $ν$ oscillation experiments implies that accurate calculations of $νA$ cross sections in this regime will be a key contributor to reducing the systematic uncertainties affecting the extraction of oscillation parameters. In spite of this, many MC$ν$EGs utilize highly phenomenological, parameterized models of QE scattering cross sections. Moreover, a culture of validation of MC$ν$EGs against prolific electron ($e$) scattering data has been historically lacking. In this work, we implement new $e A$ cross sections obtained from nuclear ab initio approaches in GENIE, the primary MC$ν$EG utilized by the FNAL community. In particular, we utilize results from Quantum MC methods which solve the many-body nuclear problem in the Short-Time Approximation (STA), allowing consistent retention of two-nucleon dynamics which are crucial to explain available nuclear electromagnetic (electroweak) data over a wide range of energy and momentum transfers. This new implementation in GENIE is fully tested against the world QE electromagnetic data, finding agreement with available data below $\sim2\,$GeV of beam energy with the aid of a scaling function formalism. The STA is currently limited to study $A\leq12$ nuclei, however, its semi-inclusive multibody identity components are exportable to other many-body computational techniques such as Auxiliary Field Diffusion MC which can reach $A\leq40$ systems while continuing to realize the factorization contained within the STA's multinucleon dynamics. Together, these developments promise to make future experiments such as DUNE more accurate in their assessment of MC$ν$EG systematics, $ν$ properties, and potentially empower the discovery of physics beyond the Standard Model.

nucl-th↗

arXiv2019

Quantum Computing for Neutrino-nucleus Scattering

Neutrino-nucleus cross section uncertainties are expected to be a dominant systematic in future accelerator neutrino experiments. The cross sections are determined by the linear response of the nucleus to the weak interactions of the neutrino, and are dominated by energy and distance scales of the order of the separation between nucleons in the nucleus. These response functions are potentially an important early physics application of quantum computers. Here we present an analysis of the resources required and their expected scaling for scattering cross section calculations. We also examine simple small-scale neutrino-nucleus models on modern quantum hardware. In this paper, we use variational methods to obtain the ground state of a three nucleon system (the triton) and then implement the relevant time evolution. In order to tame the errors in present-day NISQ devices, we explore the use of different error-mitigation techniques to increase the fidelity of the calculations.

quant-ph↗

arXiv2019

Quasielastic lepton scattering and back-to-back nucleons in the short-time approximation

Understanding quasielastic electron- and neutrino-scattering from nuclei has taken on new urgency with current and planned neutrino oscillation experiments, and with electron scattering experiments measuring specific final states, such as those involving nucleon pairs in ``back-to-back'' configurations. Accurate many-body methods are available for calculating the response of light ($A \leq 12$) nuclei to electromagnetic and weak probes, but they are computationally intensive and only applicable to the inclusive response. In the present work we introduce a novel approach, based on realistic models of nuclear interactions and currents, to evaluate the short-time (high-energy) inclusive and exclusive response of nuclei. The approach accounts reliably for crucial two-nucleon dynamics, including correlations and currents, and provides information on back-to-back nucleons observed in electron and neutrino scattering experiments. We demonstrate that in the quasielastic regime and at moderate momentum transfers both initial- and final-state correlations, and two-nucleon currents are important for a quantitatively successful description of the inclusive response and final state nucleons. Finally, the approach can be extended to include relativistic---kinematical and dynamical---effects, at least approximately in the two-nucleon sector, and to describe the response in the resonance-excitation region.

nucl-th↗