About

Guido Pagano is a Research Professor at Rice University and the Principal Investigator of the Pagano Research Group. His research focuses on quantum simulation, as indicated by the group's name, and he is involved in exploring advanced topics in quantum physics and related computational methods. The page lists his contact email as pagano at rice.edu and references his CV and Google Scholar profile, suggesting an active engagement in scholarly research and publication. The group includes graduate students, undergraduate students, and international visitors, highlighting a collaborative environment dedicated to advancing knowledge in quantum science.

Research topics

• Computer Science
• Physics
• Artificial Intelligence
• Political Science
• Quantum mechanics
• Library science
• Mathematical optimization
• Engineering
• Algorithm
• Public relations
• Mathematics
• Statistical physics
• Condensed matter physics
• Engineering ethics
• Law
• Atomic physics

Selected publications

• Monolithic Segmented 3D Ion Trap for Quantum Technology Applications

  arXiv (Cornell University) · 2026-03-17

  articleOpen access

  Monolithic three-dimensional (3D) Paul traps combine the high-precision microfabrication of two-dimensional (2D) chip traps with the deep trapping potentials and low heating rates characteristic of macroscopic 3D Paul traps, which are typically machined by traditional means and mechanically assembled. However, achieving low motional heating rates and optical access with a high numerical aperture (NA) while maintaining the high radio-frequency (RF) voltages required for trapping heavy ionic species, such as Yb$^{+}$ and Ba$^{+}$, remains a significant technical challenge. In this work, we present a fused-silica, monolithic segmented 3D Paul trap with an ion-electrode distance of 250 $μ$m, and stable operation at high RF voltages. We benchmark the performance of the trap using Yb$^{+}$ ions, demonstrating axially homogeneous trapping potentials spanning over 200 $μ$m about the axial center of the trap, high multi-directional optical access (up to 0.7 NA), and radial motional heating as low as $\dot{\bar n}=1.1 \pm 0.1 $ quanta/s at radial trap frequencies about 3 MHz near room temperature. Furthermore, we observe a motional Ramsey coherence time, ${T}_{2}$, of about 95 ms for the radial center-of-mass mode. We demonstrate the generation of a two-qubit Bell state with a parity contrast of ${99.3}^{+0.7} _{-1.5}$% with state preparation and measurement correction. These results establish fused-silica monolithic 3D Paul traps as a scalable, modular platform for quantum simulation, computation, metrology, and networking with heavy ionic species.

  PublisherOA PDF

• Monolithic Segmented 3D Ion Trap for Quantum Technology Applications

  arXiv (Cornell University) · 2026-03-17

  preprintOpen access

  Monolithic three-dimensional (3D) Paul traps combine the high-precision microfabrication of two-dimensional (2D) chip traps with the deep trapping potentials and low heating rates characteristic of macroscopic 3D Paul traps, which are typically machined by traditional means and mechanically assembled. However, achieving low motional heating rates and optical access with a high numerical aperture (NA) while maintaining the high radio-frequency (RF) voltages required for trapping heavy ionic species, such as Yb$^{+}$ and Ba$^{+}$, remains a significant technical challenge. In this work, we present a fused-silica, monolithic segmented 3D Paul trap with an ion-electrode distance of 250 $μ$m, and stable operation at high RF voltages. We benchmark the performance of the trap using Yb$^{+}$ ions, demonstrating axially homogeneous trapping potentials spanning over 200 $μ$m about the axial center of the trap, high multi-directional optical access (up to 0.7 NA), and radial motional heating as low as $\dot{\bar n}=1.1 \pm 0.1 $ quanta/s at radial trap frequencies about 3 MHz near room temperature. Furthermore, we observe a motional Ramsey coherence time, ${T}_{2}$, of about 95 ms for the radial center-of-mass mode. We demonstrate the generation of a two-qubit Bell state with a parity contrast of ${99.3}^{+0.7} _{-1.5}$% with state preparation and measurement correction. These results establish fused-silica monolithic 3D Paul traps as a scalable, modular platform for quantum simulation, computation, metrology, and networking with heavy ionic species.

  PublisherDOI

• Quantum simulation of charge and exciton transfer in multi-mode models using engineered reservoirs

  Nature Communications · 2025-12-05

  articleOpen accessSenior author

  Quantum simulation enables studies of open-system dynamics in non-perturbative regimes by programming electronic, vibrational, and environmental interactions on comparable energy scales. Trapped ions offer this capability, combining spins, phonons, and tunable dissipation on one platform. We demonstrate an open-system quantum simulation of charge and exciton transfer in a multi-mode linear vibronic coupling model. Using tailored spin-phonon interactions with reservoir engineering, we emulate a system with two dissipative vibrational modes coupled to donor and acceptor sites and track its non-equilibrium dynamics. We continuously tune the system from the charge transfer regime to the vibrationally assisted exciton transfer regime and find that degenerate modes enhance transfer rates at large energy gaps, while non-degenerate modes activate pathways that reduce the energy-gap dependence. Thus, the presence of one additional vibration introduces interfering pathways and reshapes non-perturbative excitation transfer. Our results establish a scalable, hardware-efficient route to simulate vibronic processes with engineered environments. Recent developments in trapped-ion platforms are opening towards quantum simulation of chemical dynamics. Here, the authors demonstrate independent control of spin-phonon coupling and reservoir engineering in a two-mode trapped-ion system to simulate excitation transfer dynamics.

  PublisherOA PDFDOI

• Quantum Simulation of Charge and Exciton Transfer in Multi-mode Models using Engineered Reservoirs

  ArXiv.org · 2025-05-28

  preprintOpen accessSenior author

  Quantum simulation offers a route to study open-system molecular dynamics in non-perturbative regimes by programming the interactions among electronic, vibrational, and environmental degrees of freedom on similar energy scales. Trapped-ion systems possess this capability, with their native spins, phonons, and tunable dissipation integrated within a single platform. Here, we demonstrate an open-system quantum simulation of charge and exciton transfer in a multi-mode linear vibronic coupling model. Employing tailored spin-phonon interactions alongside reservoir engineering techniques, we emulate a system with two dissipative vibrational modes coupled to donor and acceptor electronic sites and follow its non-equilibrium dynamics. We continuously tune the system from the charge transfer (CT) regime to the vibrationally assisted exciton transfer (VAET) regime by controlling the vibronic coupling strengths. We find that degenerate modes enhance CT and VAET rates at large energy gaps, while non-degenerate modes activate slow-mode pathways that reduce the energy-gap dependence, thus enlarging the window for efficient transfer. These results show that the presence of one additional vibration introduces interfering vibrationally assisted pathways and reshapes non-perturbative quantum excitation transfer. Our work establishes a scalable and hardware-efficient route to simulating chemically relevant, many-mode vibronic processes with engineered environments, guiding the design of next-generation organic photovoltaics and molecular electronics.

  PublisherOA PDFDOI

• Delocalized Excitation Transfer in Open Quantum Systems with Long-Range Interactions

  PRX Quantum · 2025-10-01 · 1 citations

  articleOpen accessSenior author

  The interplay between coherence and system-environment interactions is at the basis of a wide range of phenomena, from quantum information processing to charge and energy transfer in molecular systems, biomolecules, and photochemical materials. In this work, we use a Frenkel exciton model with long-range interacting qubits coupled to a damped collective bosonic mode to investigate vibrationally assisted transfer processes in donor-acceptor systems featuring internal substructures analogous to light-harvesting complexes. We find that certain delocalized excitonic states maximize the transfer rate and that the entanglement is preserved during the dissipative transfer over a wide range of parameters. We investigate the reduction in transfer caused by static disorder, white noise, and finite temperature and study how transfer efficiency scales as a function of the number of dimerized monomers and the component number of each monomer, finding which excitonic states lead to optimal transfer. Finally, we provide a realistic experimental setting to realize this model in analog trapped-ion quantum simulators. Analog quantum simulation of systems comprising many and increasingly complex monomers could offer valuable insights into the design of light-harvesting materials, particularly in the nonperturbative intermediate parameter regime examined in this study, where classical simulation methods are resource intensive.

  PublisherDOI

• Non-equilibrium critical scaling and universality in a quantum simulator

  Nature Communications · 2025-08-26 · 1 citations

  articleOpen access

  Universality and scaling laws are hallmarks of equilibrium phase transitions and critical phenomena. However, extending these concepts to non-equilibrium systems is an outstanding challenge. Despite recent progress in the study of dynamical phases, the universality classes and scaling laws for non-equilibrium phenomena are far less understood than those in equilibrium. In this work, using a trapped-ion quantum simulator with single-spin resolution, we investigate the non-equilibrium nature of critical fluctuations following a quantum quench to the critical point. We probe the scaling of spin fluctuations after a series of quenches to the critical Hamiltonian of a long-range Ising model. With systems of up to 50 spins, we show that the amplitude and timescale of the post-quench fluctuations scale with system size with distinct universal critical exponents, depending on the quench protocol. While a generic quench can lead to thermal critical behavior, we find that a second quench from one critical state to another (i.e. a double quench) results in a new universal non-equilibrium behavior, identified by a set of critical exponents distinct from their equilibrium counterparts. Our results demonstrate the ability of quantum simulators to explore universal scaling beyond equilibrium.

  PublisherOA PDFDOI

• Dataset for "Precision Measurement of Lifetime and Branching Ratios of the 4f^{13}5d6s ^1[5/2]_{5/2} state in Yb^+ ions"

  ArXiv.org · 2025-06-04

  preprintOpen accessSenior author

  We report spectroscopic and time-resolved experimental observations to characterize the $[{\rm Xe}]4f^{13}(^2F^{o}_{5/2}){5d6s(}{^1\!D}){^{1}[5/2]^{o}_{5/2}}$ state in $^{172}$Yb$^+$ ions. We access this state from the metastable $4f^{14}5d (^2D_{3/2,5/2})$ manifold and observe an unexpectedly long lifetime of $τ=37.9(9) \,μ$s that allows visible Rabi oscillations and resolved-sideband spectroscopy. Using a combination of coherent population dynamics, high-fidelity detection and heralded state preparation, and optical pumping methods, we measure the branching ratios to the $^{2}D_{3/2}$, $^2D_{5/2}$, $^2S_{1/2}$ states to be 0.359(2), 0.639(2), 0.0023(16), respectively. The branching ratio to the $4f^{13}6s^{2}({^2F}_{7/2})$ is compatible with zero within our experimental resolution. We also report measurements of its Landé g-factor and the branching ratio of the ${^{2}{D}_{5/2}}$ to ${^{2}{S}_{1/2}}$ decay in $^{172}$Yb$^+$ to be 0.188(3), improving its relative uncertainty by an order of magnitude. Our measurements pave the way to a better understanding of the atomic structure of Yb$^+$ ions, which still lacks accurate numerical descriptions, and the use of high-lying excited states for partial detection and qubit manipulation in the omg architecture.

  PublisherOA PDFDOI

• Quantum Simulation of Charge and Exciton Transfer in Multi-mode Models with Engineered Reservoirs

  Research Square · 2025-07-31 · 1 citations

  preprintOpen accessSenior author
  PublisherOA PDFDOI

• Precision measurement of lifetime and branching ratios of the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mn>4</mml:mn> <mml:msup> <mml:mi>f</mml:mi> <mml:mn>13</mml:mn> </mml:msup> <mml:mn>5</mml:mn> <mml:mi>d</mml:mi> <mml:mn>6</mml:mn> <mml:msup> <mml:mi>s</mml:mi> <mml:mn>1</mml:mn> </mml:msup> <mml:msub> <mml:mrow> <mml:mo>[</mml:mo> <mml:mn>5</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> <mml:mo>]</mml:mo> </mml:mrow> <mml:mrow> <mml:mn>5</mml:mn> <mml:mo>/</mml:mo> <mml:mn>2</mml:mn> </mml:mrow> </mml:msub> </mml:mrow> </mml:math> state in <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:msup> <mml:mrow> <mml:mi>Yb</mml:mi> </mml:mrow> <mml:mo>+</mml:mo> </mml:msup> </mml:math> ions

  Physical Review Research · 2025-09-23 · 1 citations

  articleOpen accessSenior author

  We report spectroscopic and time-resolved experimental observations to characterize the <a:math xmlns:a="http://www.w3.org/1998/Math/MathML"> <a:mrow> <a:mrow> <a:mo>[</a:mo> <a:mi>Xe</a:mi> <a:mo>]</a:mo> </a:mrow> <a:mn>4</a:mn> <a:msup> <a:mi>f</a:mi> <a:mn>13</a:mn> </a:msup> <a:mrow> <a:mo>(</a:mo> <a:mmultiscripts> <a:mi>F</a:mi> <a:mrow> <a:mn>5</a:mn> <a:mo>/</a:mo> <a:mn>2</a:mn> </a:mrow> <a:mi>o</a:mi> <a:mprescripts/> <a:none/> <a:mn>2</a:mn> </a:mmultiscripts> <a:mo>)</a:mo> </a:mrow> <a:mn>5</a:mn> <a:mi>d</a:mi> <a:mn>6</a:mn> <a:mi>s</a:mi> <a:mrow> <a:mo>(</a:mo> <a:mmultiscripts> <a:mi>D</a:mi> <a:mprescripts/> <a:none/> <a:mn>1</a:mn> </a:mmultiscripts> <a:mo>)</a:mo> </a:mrow> <a:mrow> <a:msup> <a:mrow/> <a:mn>1</a:mn> </a:msup> <a:msubsup> <a:mrow> <a:mo>[</a:mo> <a:mn>5</a:mn> <a:mo>/</a:mo> <a:mn>2</a:mn> <a:mo>]</a:mo> </a:mrow> <a:mrow> <a:mn>5</a:mn> <a:mo>/</a:mo> <a:mn>2</a:mn> </a:mrow> <a:mi>o</a:mi> </a:msubsup> </a:mrow> </a:mrow> </a:math> state in <b:math xmlns:b="http://www.w3.org/1998/Math/MathML"> <b:mmultiscripts> <b:mi>Yb</b:mi> <b:none/> <b:mo>+</b:mo> <b:mprescripts/> <b:none/> <b:mn>172</b:mn> </b:mmultiscripts> </b:math> ions. We access this state from the metastable <c:math xmlns:c="http://www.w3.org/1998/Math/MathML"> <c:mrow> <c:mn>4</c:mn> <c:msup> <c:mi>f</c:mi> <c:mn>14</c:mn> </c:msup> <c:mn>5</c:mn> <c:mi>d</c:mi> <c:mrow> <c:mo>(</c:mo> <c:mmultiscripts> <c:mi>D</c:mi> <c:mrow> <c:mn>3</c:mn> <c:mo>/</c:mo> <c:mn>2</c:mn> <c:mo>,</c:mo> <c:mn>5</c:mn> <c:mo>/</c:mo> <c:mn>2</c:mn> </c:mrow> <c:none/> <c:mprescripts/> <c:none/> <c:mn>2</c:mn> </c:mmultiscripts> <c:mo>)</c:mo> </c:mrow> </c:mrow> </c:math> manifold and observe an unexpectedly long lifetime of <d:math xmlns:d="http://www.w3.org/1998/Math/MathML"> <d:mrow> <d:mi>τ</d:mi> <d:mo>=</d:mo> <d:mn>37.9</d:mn> <d:mo>(</d:mo> <d:mn>9</d:mn> <d:mo>)</d:mo> <d:mspace width="0.16em"/> <d:mi>µ</d:mi> <d:mi mathvariant="normal">s</d:mi> </d:mrow> </d:math> that allows visible Rabi oscillations and resolved-sideband spectroscopy. Using a combination of coherent population dynamics, high-fidelity detection and heralded state preparation, and optical pumping methods, we measure the branching ratios to the <g:math xmlns:g="http://www.w3.org/1998/Math/MathML"> <g:mmultiscripts> <g:mi>D</g:mi> <g:mrow> <g:mn>3</g:mn> <g:mo>/</g:mo> <g:mn>2</g:mn> </g:mrow> <g:none/> <g:mprescripts/> <g:none/> <g:mn>2</g:mn> </g:mmultiscripts> <g:mo>,</g:mo> <g:mo> </g:mo> <g:mmultiscripts> <g:mi>D</g:mi> <g:mrow> <g:mn>5</g:mn> <g:mo>/</g:mo> <g:mn>2</g:mn> </g:mrow> <g:none/> <g:mprescripts/> <g:none/> <g:mn>2</g:mn> </g:mmultiscripts> </g:math> , and <h:math xmlns:h="http://www.w3.org/1998/Math/MathML"> <h:mmultiscripts> <h:mi>S</h:mi> <h:mrow> <h:mn>1</h:mn> <h:mo>/</h:mo> <h:mn>2</h:mn> </h:mrow> <h:none/> <h:mprescripts/> <h:none/> <h:mn>2</h:mn> </h:mmultiscripts> </h:math> states to be <i:math xmlns:i="http://www.w3.org/1998/Math/MathML"> <i:mrow> <i:mn>0.359</i:mn> <i:mo>(</i:mo> <i:mn>2</i:mn> <i:mo>)</i:mo> </i:mrow> </i:math> , 0.639(2), and <j:math xmlns:j="http://www.w3.org/1998/Math/MathML"> <j:mrow> <j:mn>0.0023</j:mn> <j:mo>(</j:mo> <j:mn>16</j:mn> <j:mo>)</j:mo> </j:mrow> </j:math> , respectively. The branching ratio to the <k:math xmlns:k="http://www.w3.org/1998/Math/MathML"> <k:mrow> <k:mn>4</k:mn> <k:msup> <k:mi>f</k:mi> <k:mn>13</k:mn> </k:msup> <k:mn>6</k:mn> <k:msup> <k:mi>s</k:mi> <k:mn>2</k:mn> </k:msup> <k:mrow> <k:mo>(</k:mo> <k:msub> <k:mrow> <k:mmultiscripts> <k:mi>F</k:mi> <k:mprescripts/> <k:none/> <k:mrow> <k:mn>2</k:mn> </k:mrow> </k:mmultiscripts> </k:mrow> <k:mrow> <k:mn>7</k:mn> <k:mo>/</k:mo> <k:mn>2</k:mn> </k:mrow> </k:msub> <k:mo>)</k:mo> </k:mrow> </k:mrow> </k:math> is compatible with zero within our experimental resolution. We also report measurements of Landé <l:math xmlns:l="http://www.w3.org/1998/Math/MathML"> <l:mi>g</l:mi> </l:math> -factor of the <m:math xmlns:m="http://www.w3.org/1998/Math/MathML"> <m:mrow> <m:msup> <m:mrow/> <m:mn>1</m:mn> </m:msup> <m:msubsup> <m:mrow> <m:mo>[</m:mo> <m:mn>5</m:mn>

  PublisherDOI

• Experimental Realization of Thermal Reservoirs with Tunable Temperature in a Trapped-Ion Spin-Boson Simulator

  arXiv (Cornell University) · 2025-11-11

  preprintOpen accessSenior author

  We propose and demonstrate an experimental scheme to engineer thermal baths with independently tunable temperatures and dissipation rates for the motional modes of a trapped-ion system. This approach enables robust thermal-state preparation and quantum simulations of open-system dynamics in bosonic and spin-boson models at well-controlled finite temperatures. We benchmark our protocol by experimentally realizing out-of-equilibrium dynamics of a charge-transfer model at different temperatures. We observe that, when the process occurs at a higher temperature, the transfer rate spectrum broadens, with reduced rates at small donor-acceptor energy gaps and enhanced rates at large gaps. We then employ our scheme to study local-temperature effects in a two-mode vibrationally assisted exciton transfer system, where we observe thermally activated interference pathways for excitation transfer.

  PublisherOA PDFDOI

Recent grants

• CAREER: Taming Entanglement in Open Quantum Systems

  NSF · $704k · 2022–2026

Frequent coauthors

• C. Monroe

  Keck Hospital of USC

  152 shared

• Alexey V. Gorshkov

  89 shared

• Patrick Becker

  88 shared

• Harvey Kaplan

  Joint Quantum Institute

  87 shared

• A. Kyprianidis

  85 shared

• Paul Hess

  Middlebury College

  75 shared

• Wen Lin Tan

  Hunan Institute of Science and Technology

  74 shared

• Arinjoy De

  Joint Quantum Institute

  56 shared

Labs

• Pagano Research GroupPI

Education

• PhD, Physics

  Scuola Normale Superiore

  2015

• Master of Science, Physics

  Università degli Studi di Roma La Sapienza Dipartimento di Fisica

  2011

• Bachelor, Physics

  Università degli Studi di Milano Dipartimento di Fisica

  2009

• Bachelor, Economics

  Università Bocconi

  2006