About

Jonathan Simon is a Professor of Physics and Applied Physics at Stanford University. His research focuses on exploring the implications of the laws of quantum mechanics using strongly interacting photons. His group employs cavity quantum electrodynamics to couple photons with laser-cooled atoms, harnessing the nonlinearity of atoms to induce interactions and entanglement between photons. The group develops new tools for manipulating light and cold atoms to investigate quantum many-body states of light, with applications in quantum information processing and quantum repeaters. Simon's work includes exploring quantum matter made of strongly interacting photons, interfacing optical and microwave photons using resonators and atoms as transducers, and investigating topological cavity QED. He has a background that includes graduating from Montgomery Blair High School in 2000, Caltech in 2004, and MIT/Harvard in 2010. He was a faculty member at the University of Chicago from 2012 to 2022 before joining Stanford. His research is characterized by large team efforts and independent projects aimed at advancing quantum physics and photonics.

Research topics

• Quantum mechanics
• Physics
• Condensed matter physics
• Theoretical physics
• Quantum electrodynamics

Selected publications

• Observation of Laughlin states made of light

  Nature · 92 citations

  Senior authorCorresponding
  • Physics
  • Quantum mechanics
  • Condensed matter physics

  Abstract Much of the richness in nature emerges because simple constituents form an endless variety of ordered states1. Whereas many such states are fully characterized by symmetries2, interacting quantum systems can exhibit topological order and are instead characterized by intricate patterns of entanglement3, 4. A paradigmatic example of topological order is the Laughlin state5, which minimizes the interaction energy of charged particles in a magnetic field and underlies the fractional quantum Hall effect6. Efforts have been made to enhance our understanding of topological order by forming Laughlin states in synthetic systems of ultracold atoms7, 8 or photons9–11. Nonetheless, electron gases remain the only systems in which such topological states have been definitively observed6, 12–14. Here we create Laughlin-ordered photon pairs using a gas of strongly interacting, lowest-Landau-level polaritons as a photon collider. Initially uncorrelated photons enter a cavity and hybridize with atomic Rydberg excitations to form polaritons15–17, quasiparticles that here behave like electrons in the lowest Landau level owing to a synthetic magnetic field created by Floquet engineering18 a twisted cavity11, 19 and by Rydberg-mediated interactions between them16, 17, 20, 21. Polariton pairs collide and self-organize to avoid each other while conserving angular momentum. Our finite-lifetime polaritons only weakly prefer such organization. Therefore, we harness the unique tunability of Floquet polaritons to distil high-fidelity Laughlin states of photons outside the cavity. Particle-resolved measurements show that these photons avoid each other and exhibit angular momentum correlations, the hallmarks of Laughlin physics. This work provides broad prospects for the study of topological quantum light22.

  DOI

• A second-order optical Butterworth Fabry–Pérot filter

  Review of Scientific Instruments · 2026-02-01

  articleSenior author

  Filters with flattop passbands are a key enabling technology for signal processing. From communication to sensing, the ability to choose a passband, rather than a single pass frequency, while still efficiently suppressing backgrounds at other frequencies, is a critical capability for ensuring both detection sensitivity and power efficiency. Efficient transmission of a single frequency can be achieved by a single-pole resonator—which in optics is a Fabry–Pérot cavity offering linewidths from kHz to GHz and beyond. Coupling multiple resonators allows for the construction of flattop multi-pole filters. These, although straightforward from RF to THz, where resonators are macroscopic and tunable, are more difficult to control in the optical band and typically realized with dielectric stacks, whose passband widths exceed 100 GHz. Here, we bridge the gap to narrower bandwidth flattop filters by proposing and implementing a second-order Butterworth-type optical filter in a single two-mirror Fabry–Pérot cavity by coupling the two polarization modes. We demonstrate a passband width of 2.68(1) GHz, a maximum stopband suppression of 43 dB, and a passband insertion loss of 2.2(1) dB, with out-of-band power suppression falling as the fourth power of detuning. This approach is viable down to much narrower filters and has the potential to improve high-frequency phase noise performance of lasers, enhance the sensitivity of LIDARs, and provide higher quality narrowband filtering, for example, for Raman spectroscopy.

  PublisherDOI

• The Complexity of Bank Holding Companies: A New Measurement Approach

  SSRN Electronic Journal · 2025-01-01 · 2 citations

  articleOpen accessSenior author
  PublisherDOI

• High-Fidelity Universal Gates in the <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:msup><mml:mi/><mml:mn>171</mml:mn></mml:msup></mml:math><mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML" display="inline"><mml:mi>Yb</mml:mi></mml:math> Ground-State Nuclear-Spin Qubit

  PRX Quantum · 2025-05-21 · 26 citations

  articleOpen access

  Arrays of optically trapped neutral atoms are a promising architecture for the realization of quantum computers. In order to run increasingly complex algorithms, it is advantageous to demonstrate high-fidelity and flexible gates between long-lived and highly coherent qubit states. In this work, we demonstrate a universal high-fidelity gate set with individually controlled and parallel application of single-qubit gates and two-qubit gates operating on the ground-state nuclear-spin qubit in arrays of tweezer-trapped <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi/><a:mn>171</a:mn></a:msup></a:math><c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:mi>Yb</c:mi></c:math> atoms. We utilize the long lifetime, flexible control, and high gate fidelity of our system to characterize native gates using single- and two-qubit Clifford and symmetric subspace randomized-benchmarking circuits with more than 200 controlled-<e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:mi>Z</e:mi></e:math> () gates applied to one or two pairs of atoms. We measure our two-qubit entangling gate fidelity to be 99.72(3)% (99.40(3)%) with (without) postselection. In addition, we introduce a simple and optimized method for calibration of multiparameter quantum gates. These results represent important milestones toward executing complex and general quantum computation with neutral atoms.

  PublisherOA PDFDOI

• Repeated ancilla reuse for logical computation on a neutral atom quantum computer

  ArXiv.org · 2025-06-11

  preprintOpen access

  Quantum processors based on neutral atoms trapped in arrays of optical tweezers have appealing properties, including relatively easy qubit number scaling and the ability to engineer arbitrary gate connectivity with atom movement. However, these platforms are inherently prone to atom loss, and the ability to replace lost atoms during a quantum computation is an important but previously elusive capability. Here, we demonstrate the ability to measure and re-initialize, and if necessary replace, a subset of atoms while maintaining coherence in other atoms. This allows us to perform logical circuits that include single and two-qubit gates as well as repeated midcircuit measurement while compensating for atom loss. We highlight this capability by performing up to 41 rounds of syndrome extraction in a repetition code, and combine midcircuit measurement and atom replacement with real-time conditional branching to demonstrate heralded state preparation of a logically encoded Bell state. Finally, we demonstrate the ability to replenish atoms in a tweezer array from an atomic beam while maintaining coherence of existing atoms -- a key step towards execution of logical computations that last longer than the lifetime of an atom in the system.

  PublisherOA PDFDOI

• Millimeter-Wave Superconducting Qubit

  PRX Quantum · 2025-05-23 · 19 citations

  articleOpen access

  Manipulating the electromagnetic spectrum at the single-photon level is fundamental for quantum experiments. In the visible and infrared ranges, this can be accomplished with atomic quantum emitters, and with superconducting qubits such control is extended to the microwave range (below 10 GHz). Meanwhile, the region between these two energy ranges presents an unexplored opportunity for innovation. We bridge this gap by scaling up a superconducting qubit to the millimeter-wave range (near 100 GHz). Working in this energy range greatly reduces sensitivity to thermal noise compared to microwave devices, enabling operation at significantly higher temperatures, up to 1 K. This has many advantages by removing the dependence on rare <a:math xmlns:a="http://www.w3.org/1998/Math/MathML" display="inline"><a:msup><a:mi/><a:mn>3</a:mn></a:msup><a:mi>He</a:mi></a:math> for refrigeration, simplifying cryogenic systems, and providing orders-of-magnitude higher cooling power, lending the flexibility needed for novel quantum sensing and hybrid experiments. Using low-loss niobium trilayer junctions, we realize a qubit at 72 GHz cooled to 0.87 K using only <c:math xmlns:c="http://www.w3.org/1998/Math/MathML" display="inline"><c:msup><c:mi/><c:mn>4</c:mn></c:msup><c:mi>He</c:mi></c:math>. We perform Rabi oscillations to establish control over the qubit state, and measure relaxation and dephasing times of 15.8 and 17.4 ns, respectively. This demonstration of a millimeter-wave quantum emitter offers exciting prospects for enhanced sensitivity thresholds in high-frequency photon detection, provides new options for quantum transduction and for scaling up and speeding up quantum computing, enables integration of quantum systems where <e:math xmlns:e="http://www.w3.org/1998/Math/MathML" display="inline"><e:msup><e:mi/><e:mn>3</e:mn></e:msup><e:mi>He</e:mi></e:math> refrigeration units are impractical, and, importantly, paves the way for quantum experiments exploring a novel energy range.

  PublisherOA PDFDOI

• Repeated Ancilla Reuse for Logical Computation on a Neutral Atom Quantum Computer

  Physical Review X · 2025-10-16 · 5 citations

  articleOpen access

  Quantum processors based on neutral atoms trapped in arrays of optical tweezers have appealing properties, including relatively easy qubit number scaling and the ability to engineer arbitrary gate connectivity with atom movement. However, these platforms are inherently prone to atom loss, and the ability to replace lost atoms during a quantum computation is an important but previously elusive capability. Here, we demonstrate the ability to measure and reinitialize, and if necessary replace, a subset of atoms while maintaining coherence in other atoms. This allows us to perform logical circuits that include single- and two-qubit gates as well as repeated midcircuit measurement while compensating for atom loss. We highlight this capability by performing up to 41 rounds of syndrome extraction in a repetition code, and combine midcircuit measurement and atom replacement with real-time conditional branching to demonstrate heralded state preparation of a logically encoded Bell state. Finally, we demonstrate the ability to replenish atoms in a tweezer array from an atomic beam while maintaining coherence of existing atoms—a key step toward execution of logical computations that last longer than the lifetime of an atom in the system.

  PublisherDOI

• Superconducting Qubits Above 20 GHz Operating over 200 mK

  arXiv (Cornell University) · 2024-02-05 · 2 citations

  preprintOpen access

  Current state-of-the-art superconducting microwave qubits are cooled to extremely low temperatures to avoid sources of decoherence. Higher qubit operating temperatures would significantly increase the cooling power available, which is desirable for scaling up the number of qubits in quantum computing architectures and integrating qubits in experiments requiring increased heat dissipation. To operate superconducting qubits at higher temperatures, it is necessary to address both quasiparticle decoherence (which becomes significant for aluminum junctions above 160 mK) and dephasing from thermal microwave photons (which are problematic above 50 mK). Using low-loss niobium trilayer junctions, which have reduced sensitivity to quasiparticles due to niobium's higher superconducting transition temperature, we fabricate transmons with higher frequencies than previously studied, up to 24 GHz. We measure decoherence and dephasing times of about 1 us, corresponding to average qubit quality factors of approximately $10^5$, and find that decoherence is unaffected by quasiparticles up to 1 K. Without relaxation from quasiparticles, we are able to explore dephasing from purely thermal sources, finding that our qubits can operate up to approximately 250 mK while maintaining similar performance. The thermal resilience of these qubits creates new options for scaling up quantum processors, enables hybrid quantum experiments with high heat dissipation budgets, and introduces a material platform for even higher-frequency qubits.

  PublisherOA PDFDOI

• Manybody interferometry of quantum fluids

  Science Advances · 2024-07-19 · 8 citations

  articleOpen access

  Characterizing strongly correlated matter is an increasingly central challenge in quantum science, where structure is often obscured by massive entanglement. It is becoming clear that in the quantum regime, state preparation and characterization should not be treated separately-entangling the two processes provides a quantum advantage in information extraction. Here, we present an approach that we term "manybody Ramsey interferometry" that combines adiabatic state preparation and Ramsey spectroscopy: Leveraging our recently developed one-to-one mapping between computational-basis states and manybody eigenstates, we prepare a superposition of manybody eigenstates controlled by the state of an ancilla qubit, allow the superposition to evolve relative phase, and then reverse the preparation protocol to disentangle the ancilla while localizing phase information back into it. Ancilla tomography then extracts information about the manybody eigenstates, the associated excitation spectrum, and thermodynamic observables. This work illustrates the potential for using quantum computers to efficiently probe quantum matter.

  PublisherOA PDFDOI

• Millimeter-Wave Superconducting Qubit

  arXiv (Cornell University) · 2024-11-17 · 1 citations

  preprintOpen access

  Manipulating the electromagnetic spectrum at the single-photon level is fundamental for quantum experiments. In the visible and infrared range, this can be accomplished with atomic quantum emitters, and with superconducting qubits such control is extended to the microwave range (below 10 GHz). Meanwhile, the region between these two energy ranges presents an unexplored opportunity for innovation. We bridge this gap by scaling up a superconducting qubit to the millimeter-wave range (near 100 GHz). Working in this energy range greatly reduces sensitivity to thermal noise compared to microwave devices, enabling operation at significantly higher temperatures, up to 1 K. This has many advantages by removing the dependence on rare $^3$He for refrigeration, simplifying cryogenic systems, and providing orders of magnitude higher cooling power, lending the flexibility needed for novel quantum sensing and hybrid experiments. Using low-loss niobium trilayer junctions, we realize a qubit at 72 GHz cooled to 0.87 K using only $^4$He. We perform Rabi oscillations to establish control over the qubit state, and measure relaxation and dephasing times of 15.8 and 17.4 ns respectively. This demonstration of a millimeter-wave quantum emitter offers exciting prospects for enhanced sensitivity thresholds in high-frequency photon detection, provides new options for quantum transduction and for scaling up and speeding up quantum computing, enables integration of quantum systems where $^3$He refrigeration units are impractical, and importantly paves the way for quantum experiments exploring a novel energy range.

  PublisherOA PDFDOI

Recent grants

• Physical Knots

  NSF · $177k · 2001–2006

Frequent coauthors

• David Schuster

  Electronics for Imaging (United States)

  53 shared

• Vladan Vuletić

  MIT-Harvard Center for Ultracold Atoms

  53 shared

• Haruka Tanji

  Fukushima Medical University Hospital

  49 shared

• Ruichao Ma

  41 shared

• Saikat Ghosh

  30 shared

• Ningyuan Jia

  30 shared

• Nathan Schine

  29 shared

• Ariel Sommer

  26 shared

Labs

• The Simon LabPI

  Synthesizes and studies the properties of topological and otherwise exotic quantum materials, especially those made of photons.

Education

• PhD, Physics

  Harvard University

  2010

• Bachelor of Science, Physics

  California Institute of Technology

  2004