About

Dirk Bouwmeester is a professor in the Department of Physics at UC Santa Barbara. His research investigates topics related to quantum information science and quantum decoherence, utilizing optomechanical systems such as phononic crystal membranes made out of silicon nitride and diamond, as well as on-chip optical waveguides coupled to superfluid Helium. His work focuses on exploring the fundamental aspects of quantum mechanics and developing technologies in the field of quantum physics.

Research topics

• Physics
• Optoelectronics
• Optics
• Materials science
• Quantum mechanics

Selected publications

• Towards fibre-like loss for photonic integration from violet to near-infrared

  Nature · 2026-01-07 · 1 citations

  articleOpen access

  Over the past decades, remarkable progress has been made in reducing the loss of photonic integrated circuits (PICs) within the telecom band1–4, facilitating on-chip applications spanning low-noise optical5 and microwave synthesis6, to lidar7 and photonic artificial intelligence engines8. However, several obstacles arise from the marked increase in material absorption and scattering losses at shorter wavelengths9,10, which prominently elevate power requirements and limit performance in the visible and near-visible spectrum. Here we present an ultralow-loss PIC platform based on germano-silicate—the material underlying the extraordinary performance of optical fibre—but realized by a fully CMOS-foundry-compatible process. These PICs achieve resonator Q factors surpassing 180 million from violet to telecom wavelengths. They also attain a 10-dB higher quality factor without thermal treatment in the telecom band, expanding opportunities for heterogeneous integration with active components11. Other features of this platform include readily engineered waveguide dispersion, acoustic mode confinement and large-mode-area-induced thermal stability—each demonstrated by soliton microcomb generation, stimulated Brillouin lasing and low-frequency-noise self-injection locking, respectively. The success of these germano-silicate PICs can ultimately enable fibre-like loss onto a chip, leading to an additional 20-dB improvement in waveguide loss over the current highest performance photonic platforms. Moreover, the performance abilities demonstrated here bridge ultralow-loss PIC technology to optical clocks12, precision navigation systems13 and quantum sensors14. Germano-silicate used as a building material for integrated photonics circuits substantially reduces optical losses, approaching levels comparable to those in optical fibres.

  PublisherOA PDFDOI

• Modeling Quantum Optomechanical STIRAP

  arXiv (Cornell University) · 2026-03-30

  articleOpen accessSenior author

  Quantum optomechanical STIRAP (Stimulated Raman Adiabatic Passage) is investigated for a system of two mechanical modes coupled to an optical mode. We show analytically that in a system without loss, fractional STIRAP can generate a mechanical Bell state from a single phonon Fock state of one of the mechanical modes with the other mechanical mode in the vacuum state, and a product state from a coherent state. Relative phases between Fock basis components in the final state of STIRAP are determined by the phonon-number parity of the initial state. Furthermore, the system is numerically studied to determine the effects of dissipation, and it is concluded that high-fidelity entanglement can be achieved via fractional STIRAP using state-of-the-art cryogenic cooling and mechanical devices. Finally, an interferometric protocol using time-reversed fractional STIRAP is proposed to quantify entanglement between two mechanical modes.

  PublisherOA PDF

• Modeling Quantum Optomechanical STIRAP

  arXiv (Cornell University) · 2026-03-30

  preprintOpen accessSenior author

  Quantum optomechanical STIRAP (Stimulated Raman Adiabatic Passage) is investigated for a system of two mechanical modes coupled to an optical mode. We show analytically that in a system without loss, fractional STIRAP can generate a mechanical Bell state from a single phonon Fock state of one of the mechanical modes with the other mechanical mode in the vacuum state, and a product state from a coherent state. Relative phases between Fock basis components in the final state of STIRAP are determined by the phonon-number parity of the initial state. Furthermore, the system is numerically studied to determine the effects of dissipation, and it is concluded that high-fidelity entanglement can be achieved via fractional STIRAP using state-of-the-art cryogenic cooling and mechanical devices. Finally, an interferometric protocol using time-reversed fractional STIRAP is proposed to quantify entanglement between two mechanical modes.

  PublisherDOI

• A spin-embedded diamond optomechanical resonator with mechanical quality factor exceeding one million

  ArXiv.org · 2025-08-08

  preprintOpen access

  Diamond optomechanical crystal (OMC) devices with embedded color center spins are promising platforms for a broad range of applications in quantum sensing, networking, and computing applications, offering an interface between a GHz-frequency mechanical mode and both optical photons and coherent spins. A crucial but elusive step towards realizing this platform is to engineer a device with a high-quality factor mechanical mode while preserving the bulk-like coherence of embedded spins. Here we demonstrate sideband-resolved diamond OMCs with mechanical quality factors in excess of $10^6$ at cryogenic temperatures, and find coherence times up to $T_2$ = 270 $μ$s for embedded nitrogen vacancy (NV) centers. Furthermore, we measure these devices across five orders of magnitude in intracavity optical power, demonstrating robust power handling and a high optomechanical cooperativity ($C\gg1$) at cryogenic temperatures that is essential for a broad range of quantum protocols requiring strong, coherent interactions between photons and phonons. These results are enabled by a robust, high-throughput method for forming single-crystal diamond membranes in combination with chemical vapor deposition (CVD) diamond overgrowth with nitrogen $δ$-doping. We discuss the prospects of this platform for hybrid spin-mechanical devices in the quantum regime.

  PublisherOA PDFDOI

• Toward a scalable single photon platform

  2025-01-01

  article

  Leveraging the intrinsic properties of III-V and oxide materials, we report the development of deterministically placed individual semiconductor quantum dots (QDs) without substrate etching, paving the way for a single photon platform at wafer scale.

  PublisherDOI

• Towards experimental demonstration of quantum position verification using single photons

  Quantum Science and Technology · 2025-07-22 · 3 citations

  articleOpen accessCorresponding

  Abstract The geographical position can be a good credential for authentication of a party. This is the basis of position-based cryptography—but classically this cannot be done securely without physical exchange of a private key. Recently it has been shown that by combining quantum mechanics with the speed-of-light limit of special relativity, this might be possible: quantum position verification (QPV). Here we demonstrate experimentally a protocol that uses two-photon Hong–Ou–Mandel interference at a beamsplitter, which, in combination with two additional beam splitters and four detectors is rendering the protocol resilient to loss. With this, we are able to show first results towards an experimental demonstration of QPV.

  PublisherDOI

• Semideterministic quantum dot placement in heteroepitaxy

  Physical Review Applied · 2025-11-06

  articleOpen accessSenior author

  Achieving deterministic placement of self-assembled quantum dots (QDs) during epitaxial growth is essential for the reliable and efficient fabrication of high-quality single-photon sources and solid-state cavity quantum electrodynamics (cQED) systems, yet it remains a significant challenge, owing to the inherent stochasticity of QD nucleation processes. In this work, we theoretically and numerically demonstrate that deterministic QD nucleation within a pristine growth region, e.g., $\mathrm{In}\mathrm{As}$ on a (001)-oriented $\mathrm{Ga}\mathrm{As}$ substrate, can be achieved by engineering the boundary geometry of that region. During epitaxial growth, adatoms initially move toward the boundary and promote the formation of primary QDs along the boundary, driven by curvature and diffusion anisotropy. The resulting primary QD distribution will generate many-body interactions that dynamically reshape the chemical potential landscape for subsequently deposited adatoms, enabling the formation of secondary QDs within the pristine growth region. These findings provide a theoretical foundation for reliable patterning of high optical-quality QDs, with potential applications in next-generation quantum photonic devices.

  PublisherOA PDFDOI

• Nonequilibrium origin of native ring anisotropy in amorphous systems

  Physical review. B./Physical review. B · 2025-05-27

  articleOpen accessSenior author

  Native ring structures within amorphous networks play a critical role in determining structural and optical properties, in part due to their ability to host dopants such as rare earth ions in silicate systems. In this work, we demonstrate that the universal features of structural anisotropy in amorphous networks can be efficiently simulated using a model based on stochastically deformed, edge sharing N member native ring structures. This model isolates and characterizes the structural anisotropy generated during the annealing quenching process that is independent of any constituent specific interactions. We refer to this computational framework as Indistinguishable Simulated Folding (ISF), a stochastic process that mimics a simulated annealing quenching procedure. Formulated as a Markov process, ISF is governed by two physically meaningful parameters: the number of Markov steps, representing the mean duration of each ring folding event, and the stochastic deformation magnitude, which quantifies thermally induced structural changes per event. Furthermore, we show that the logarithm of any positive valued anisotropy measure generated by ISF is a skewed random variable, reflecting the growing entropy production rate during the Markov evolution. ISF provides both a conceptual framework for understanding the universal stochastic origin of structural anisotropy in amorphous networks and a practical tool for simulating constituent independent features, without requiring full scale molecular dynamics simulations.

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• Mach reflection and formation of transient toroidal helium plasma

  Physical review. E · 2025-06-06

  articleOpen accessSenior author

  Laser-generated, transient toroidal helium plasma at atmospheric pressure is studied experimentally. Tomographically reconstructed cross-sectional images reveal the gas flow responsible for the formation of the toroidal structure. A splitting of the toroidal plasma during the final phase of its evolution is observed. The plasma dynamics is induced by a two-lobed plasma kernel resulting from a single, focused laser pulse. This kernel generates two shocks that join to form an enhanced third shock, a so-called Mach reflection, in the plane perpendicular to the optical axis. This shock pattern determines the gas flow, which deforms the plasma into a disk, then transforms it into a nonrotating toroid, and finally splits it into two parallel rings. Schlieren imaging, a novel laser scanning-probe imaging technique, thermodynamic modeling, and a deliberately broken flow symmetry confirm this formation mechanism. This study is of interest for the generation of compact toroidal plasma structures in free space, with potential applications in chemical reactors, laser ignition of internal combustion engines, plasma medicine, and linked magnetic field line plasma confinement.

  PublisherDOI

• Testing the Conjecture That Quantum Processes Create Conscious Experience

  Entropy · 2024-05-28 · 24 citations

  articleOpen access

  The question of what generates conscious experience has mesmerized thinkers since the dawn of humanity, yet its origins remain a mystery. The topic of consciousness has gained traction in recent years, thanks to the development of large language models that now arguably pass the Turing test, an operational test for intelligence. However, intelligence and consciousness are not related in obvious ways, as anyone who suffers from a bad toothache can attest—pain generates intense feelings and absorbs all our conscious awareness, yet nothing particularly intelligent is going on. In the hard sciences, this topic is frequently met with skepticism because, to date, no protocol to measure the content or intensity of conscious experiences in an observer-independent manner has been agreed upon. Here, we present a novel proposal: Conscious experience arises whenever a quantum mechanical superposition forms. Our proposal has several implications: First, it suggests that the structure of the superposition determines the qualia of the experience. Second, quantum entanglement naturally solves the binding problem, ensuring the unity of phenomenal experience. Finally, a moment of agency may coincide with the formation of a superposition state. We outline a research program to experimentally test our conjecture via a sequence of quantum biology experiments. Applying these ideas opens up the possibility of expanding human conscious experience through brain–quantum computer interfaces.

  PublisherOA PDFDOI

Recent grants

• Solid-State Cavity Quantum Electrodynamics

  NSF · $400k · 2009–2012

• Quantum Post-Selected Optomechanics

  NSF · $670k · 2012–2016

• NIRT: Quantum-State Transfer Between Photons and Nanostructures

  NSF · $1.6M · 2003–2008

• Quantum Superposition States of a Mirror

  NSF · $360k · 2005–2008

• MRI-R2: Nano Photonic Imaging System

  NSF · $465k · 2010–2013

Frequent coauthors

• W. Löffler

  105 shared

• M. P. van Exter

  85 shared

• Frank Buters

  Leiden University

  54 shared

• K. Heeck

  54 shared

• Henk Snijders

  52 shared

• H. J. Eerkens

  Leiden University

  52 shared

• Morten P. Bakker

  50 shared

• Nick Stoltz

  University of California, Santa Barbara

  49 shared