Josh Combes

About

Assistant Professor Josh Combes is based in the Department of Electrical, Computer and Energy Engineering at the University of Colorado Boulder. His research focuses on transforming the quantum technology landscape, particularly in the development of more reliable quantum computing components. Combes has earned a National Science Foundation CAREER Award to advance his work on designing second-generation qubits, which are significantly more error-resistant than current first-generation qubits. These low-error qubits aim to accelerate the timeline for large-scale superconducting quantum computers, which have applications in e-commerce, communications, GPS navigation, and national security. In addition to his research, Combes is dedicated to building a robust national quantum workforce. He designed a quantum engineering minor to help STEM students outside of physics become proficient in quantum technology, emphasizing the multidisciplinary nature of the field. Combes advocates for drawing expertise from various disciplines such as electrical, mechanical, and chemical engineering to foster a diverse quantum community. His efforts include mentoring students and contributing to the broader impact of quantum research through education and workforce development.

Research topics

• Computer Science
• Mathematics
• Algorithm
• Quantum mechanics
• Software engineering
• Systems engineering
• Computational science
• Engineering
• Applied mathematics
• Mathematical optimization

Selected publications

• Quantum computing with rotation-symmetric bosonic codes

  Physical Review X · 2020 · 137 citations

  Bosonic rotation codes, introduced here, are a broad class of bosonic error-correcting codes based on phase-space rotation symmetry. We present a universal quantum computing scheme applicable to a subset of this class-number-phase codes-which includes the well-known cat and binomial codes, among many others. The entangling gate in our scheme is code agnostic and can be used to interface different rotation-symmetric encodings. In addition to a universal set of operations, we propose a teleportati…

  DOI

• Building a Quantum Engineering Undergraduate Program

  IEEE Transactions on Education · 2022 · 106 citations

  <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Contribution:</i> A roadmap is provided for building a quantum engineering education program to satisfy U.S. national and international workforce needs. <italic xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">Background:</i> The rapidly growing quantum information science and engineering (QISE) industry will require both quantum-aware and quantum-proficient…

  DOI

• Squeezed dual-comb spectroscopy

  Science · 2025-01-16 · 42 citations

  article

  Optical frequency combs have enabled distinct advantages in broadband, high-resolution spectroscopy and precision interferometry. However, quantum mechanics ultimately limits the metrological precision achievable with laser frequency combs. Quantum squeezing has led to substantial measurement improvements with continuous wave lasers, but experiments demonstrating metrological advantage with squeezed combs are less developed. Using the Kerr effect in nonlinear optical fiber, a 1-gigahertz frequen…

  PublisherDOI

• Precisely determining photon-number in real time

  Quantum · 2024-05-23 · 21 citations

  articleOpen access

  Superconducting transition-edge sensors (TES) are extremely sensitive microcalorimeters used as photon detectors with unparalleled energy resolution. They have found application from measuring astronomical spectra through to determining the quantum property of photon-number, <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"><mml:mrow class="MJX-TeXAtom-ORD"><mml:mover><mml:mi>n</mml:mi><mml:mo stretchy="false">&amp;#x005E;</mml:mo></mml:mover></mml:mrow><mml:mrow class="MJX-TeXAtom-ORD"><…

  PublisherOA PDFDOI

• Nonlinear Sideband Cooling to a Cat State of Motion

  Physical Review Letters · 2023-05-25 · 19 citations

  article

  The ability to prepare a macroscopic mechanical resonator into a quantum superposition state is an outstanding goal of cavity optomechanics. Here, we propose a technique to generate cat states of motion using the intrinsic nonlinearity of a dispersive optomechanical interaction. By applying a bichromatic drive to an optomechanical cavity, our protocol enhances the inherent second-order processes of the system, inducing the requisite two-phonon dissipation. We show that this nonlinear sideband co…

  PublisherDOI

Recent grants

• CAREER: Second Generation Qubits -- the future of superconducting quantum computing

  NSF · $117k · 2023–2024

Frequent coauthors

• Howard M. Wiseman

  Centre for Quantum Computation and Communication Technology

  116 shared

• Carlton M. Caves

  University of New Mexico

  43 shared

• Christopher Ferrie

  Quantum (Australia)

  37 shared

• Ben Q. Baragiola

  34 shared

• G. J. Milburn

  29 shared

• Anushya Chandran

  Harvard University

  27 shared

• Thomas M. Stace

  University of Queensland

  25 shared

• Nathan Walk

  Freie Universität Berlin

  20 shared

Awards & honors

• National Science Foundation CAREER Award

Similar researchers at University of Colorado Boulder

• Bob Ericksonh-18