In this episode, your host Sebastian Hassinger sits down with Andrew Houck to explore the latest advancements and collaborative strategies in quantum computing. Houck shares insights from his leadership roles at both Princeton and the Center for Co-Design of Quantum Advantage (C2QA), focusing on how interdisciplinary efforts are pushing the boundaries of coherence times, materials science, and scalable quantum architectures. The conversation covers the importance of co-design across the quantum stack, the challenges and surprises in improving qubit performance, and the vision for the next era of quantum research.

KEY TOPICS DISCUSSED

• Mission of C2QA:
  The central goal is to build the components necessary to move beyond the NISQ (Noisy Intermediate-Scale Quantum) era into fault-tolerant quantum computing. This requires integrating expertise in materials, devices, software, error correction, and architecture to ensure compatibility and progress at every level.
• Materials Breakthroughs:
  Houck discusses the surprising impact of using tantalum in superconducting qubits, which has significantly reduced surface losses compared to other metals. He explains the ongoing quest to identify and mitigate sources of decoherence, such as two-level systems (TLSs) and interface defects.
• Co-Design Philosophy:
  The episode delves into two types of co-design:
  • Vertical co-design: Aligning advances in materials, devices, error correction, and architecture to optimize the full quantum computing stack.
  • Cross-platform co-design: Bridging ideas and techniques across different qubit modalities and even across disciplines, such as applying methods from quantum sensing to quantum computing.
• Error Correction Innovations:
  Houck highlights breakthroughs like using GKP states for error correction, which have achieved performance beyond the break-even point, thanks to improvements in materials and device design.
• Bosonic Modes and Custom Architectures:
  The conversation touches on leveraging native bosonic modes in hardware to simulate field theories more efficiently, potentially saving vast computational resources. Houck discusses the trade-offs between general-purpose and custom quantum circuits in the current era of limited qubit counts.
• Modular Quantum Computing:
  As quantum systems scale, the focus is shifting to modular architectures. Houck outlines the challenges of connecting modules—such as chip-to-chip coupling and optimizing connectivity for error correction and algorithms.
• Institutional Collaboration:
  Houck contrasts the long-term, foundational investment at Princeton with the national, multi-institutional mission of C2QA. He emphasizes the unique strengths universities, industry, and national labs each bring to quantum research, and the importance of fostering collaboration across these sectors.
• Looking Ahead:
  The next phase for C2QA will incorporate advances in neutral atom quantum computing and diamond-based quantum sensing, while ramping down some networking efforts. Houck also reflects on the broader scientific and practical motivations driving quantum information science, and the fundamental questions that large-scale quantum systems may help answer.

NOTABLE QUOTES

“There’s a quasi-infinite number of ways that you can mess up coherence… If you’re really only using one number, you’ll never know.”

“Some of the best ideas we have are taking approaches from one field and bringing them to another. That’s what we call cross-platform co-design.”

“A million-qubit quantum computer is basically a cat… as you build these systems up, you can start to really ask: do we actually understand quantum mechanics as it turns into these macroscopically large objects?”

RESOURCES & MENTIONS

• Center for Co-Design of Quantum Advantage (C2QA)
• Princeton Quantum Initiative

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In this episode of The New Quantum Era, Sebastian is joined by Dr. Emily Edwards, a co-founder of the Q12 initiative, an NSF-funded effort aimed at enhancing quantum science education from middle school through early undergraduate levels. Emily brings her expertise in organizing and motivating educators, as well as her passion for science communication. In this episode, we delve into the unique challenges of teaching quantum science and explore effective strategies to make this abstract field more accessible to learners of all ages.

Key Points

• Challenges in Quantum Communication and Education: Emily discusses the public perception of quantum science, often influenced by pop culture, and the importance of demystifying the subject to make it more approachable.
• Strategies for Formal and Informal Learning: The conversation highlights different techniques for teaching quantum science in formal settings, like schools, and informal settings, such as science museums or YouTube. Emily emphasizes the importance of foundational knowledge and incremental learning.
• Role of Technology in Quantum Education: Emily talks about using scanning electron microscopes and other technologies to make the invisible world of quantum science visible, thus igniting public interest and imagination similar to stargazing.
• Importance of Science Communication Workshops: Emily shares her experience in leading science communication workshops, aiming to improve the accuracy and effectiveness of science content created by the public.
• Public and Private Sector Collaboration: The discussion touches on the need for a blend of federal and private funding to sustain and scale quantum education initiatives. Emily stresses the importance of industry involvement to emphasize the urgency and importance of scientific literacy for the future workforce.

In this episode of The New Quantum Era, your host Sebastian Hassinger talks with Dr. Daniel Lidar. Dr. Lidar is a pioneering researcher in quantum computing with over 25 years of experience, currently a professor at the University of Southern California. His work spans quantum algorithms, error correction, and quantum advantage, with significant contributions to understanding quantum annealing and noise suppression techniques. Lidar has been instrumental in exploring practical quantum computing applications since the mid-1990s.

Key Topics Discussed:

• Dr. Lidar discussed how his experiments have demonstrated computational advantages on D-Wave and IBM quantum devices using innovative error suppression methods like dynamical decoupling
• We discuss Dr. Lidar's involvement in the exploration of the mechanics of quantum annealing, particularly with D-Wave devices, and its potential for solving optimization problems
• Daniel provides a detailed view of emerging approaches to error suppression, including logical dynamical decoupling (LDD) and its experimental validation
• Finally we touch on Quantum Elements, his new company focused on developing more accurate open-system quantum simulation software to improve quantum hardware performance

In this episode, Sebastian Hassinger welcomes back James Wootton, now Chief Science Officer at Moth Quantum, for a fascinating conversation about quantum computing's role in creative applications. This is a return visit from James, having appeared on episode 2, this time to talk about his exciting new role. Previously at IBM Quantum, James has been a pioneer in exploring unconventional applications of quantum computing, particularly in gaming, art, and creative industries.

Key Topics

Origins of James's Quantum Journey

• Started in Arosa, Switzerland (coincidentally where Schrödinger developed his wave equation)
• Initially skeptical about commercial applications of his quantum error correction research
• Created "Decodoku" (a play on "decoder" and "Sudoku"), a puzzle game to gamify quantum error correction in 2016
• The same year IBM put a 5 qubit machine on the cloud, creating a paradigm shift in accessibility

Quantum Gaming Innovations

• Developed what may be the first quantum computing game
• Created "Hello Quantum," a mobile educational game
• Developed "Quantum Blur," a tool that encodes images in quantum states, allowing users to see how quantum gates affect images
• Used quantum computing for procedural generation in games, including terrain generation for Minecraft-like environments

Quantum Art and Creativity

• Collaborated with a classical painter who has used Quantum Blur as his main artistic tool for five years
• Explored using quantum computing for music generation
• Investigated language generation using the DiscoCat framework

Moth Quantum

• James joined Moth Quantum as Chief Science Officer
• The company focuses on bringing quantum computing to creative industries
• Their approach recognizes that in creative fields, "usefulness" can mean bringing something unique rather than just superior performance
• Aims to build expertise with current quantum technologies to be ready when fault tolerance enables quantum advantage
• At the beginning of May, 2025, Moth collaborated with musical artist ILA on a project called "Infinite Remix," using quantum computing in the creation of an exciting new musical creation tool. 

Introduction:
In this milestone 50th episode of The New Quantum Era, your host Sebastian Hassinger welcomes Dr. Anna Grassellino, a leading figure in quantum information science and the director of the Superconducting Quantum Materials and Systems Center at Fermilab, or SQMS. Dr. Grassellino discusses the center’s mission to advance quantum computing and quantum sensing through innovations in superconducting materials and devices. The conversation explores the intersection of quantum hardware development, high energy physics applications, and the collaborative efforts driving progress in the field. We recorded our conversation at the APS 2025 Global Summit with assistance from the American Physical Society and from Quantum Machines, Inc. 

Main Topics Discussed:

• The vision and mission of the Superconducting Quantum Materials and Systems (SQMS) Center, including its role in the Department of Energy’s National Quantum Initiative and its focus on developing quantum systems with superior performance for scientific and technological applications.
• Advances in superconducting quantum hardware, particularly the use of high-quality superconducting radio frequency (SRF) cavities and their integration with two-dimensional superconducting circuits to enhance qubit coherence and scalability.
• Key technical challenges in scaling up quantum systems, such as mitigating decoherence, improving materials, and developing large-scale cryogenic platforms for quantum experiments.
• The importance of interdisciplinary collaboration between quantum engineers, materials scientists, and high energy physicists to achieve breakthroughs in quantum technology.
• Future directions for the SQMS Center, including the pursuit of quantum advantage in high energy physics algorithms, quantum sensing, and the development of robust error correction strategies.

Notable Papers from Fermi’s SQMS Center:

• Quantum computing hardware for HEP algorithms and sensing (arXiv:2204.08605) – Overview of SQMS’s approach to quantum hardware for high energy physics applications, including architectures and error correction.
• A large millikelvin platform at Fermilab for quantum computing applications (arXiv:2108.10816) – Description of the design and goals of a large-scale cryogenic platform for hosting advanced quantum devices at millikelvin temperatures.
• Searches for New Particles, Dark Matter, and Gravitational Waves 
• Additional recent preprints and publications from SQMS can be found on the SQMS Center’s publications page, including work on nonlinear quantum mechanics bounds, materials for quantum devices, and quantum error correction strategies.

Introduction

In this episode of The New Quantum Era podcast, host Sebastian Hassinger delves into an insightful conversation with Yonatan Cohen, CTO and co-founder of Quantum Machines. As a pioneer in quantum control systems, Quantum Machines is at the forefront of tackling the critical challenges of scaling quantum computing, and they also provided support for my interviews conducted at the American Physical Society’s Global Summit 2025. APS itself also graciously provided support for these episodes. 

Yonatan shares exciting updates from their latest demos at the APS conference, discusses their unique approach to quantum control, and explores how integrating classical and quantum computing is paving the way for more efficient and scalable solutions.

Key Points

• Scaling Quantum Control Systems: Yonatan discusses the challenges of scaling up quantum control systems, emphasizing the need to make systems more compact, reduce power consumption, and lower costs per qubit while maintaining high analog specifications.
• Integration of Classical Compute with Quantum Systems: The conversation highlights Quantum Machines’ collaborative work with NVIDIA on DGX Quantum, a platform that integrates classical and quantum computing to enhance computational power and low-latency data transfer.
• AI for Quantum Calibration and Error Correction: Yonatan explains the role of AI and machine learning in speeding up the calibration process of quantum computers and improving qubit control, potentially transforming how frequently and effectively quantum systems can be calibrated.
• Versatility Across Different Quantum Modalities: Quantum Machines’ control systems are adaptable to various quantum computing modalities such as superconducting qubits, NV centers, and atomic qubits, providing a flexible toolkit for researchers.
• The Role of the Israeli Quantum Computing Center: Yonatan describes Quantum Machines’ involvement in building and operating the Israeli Quantum Computing Center, providing researchers with hands-on access to cutting-edge quantum control technologies.

Welcome to episode 48 of The New Quantum Era podcast! Another episode recorded at the APS Global Summit in March, today's special guest is true quantum pioneer, John Martinis, co-founder and CTO of QoLab, a superconducting qubit company seeking to build a million qubit device. In this enlightening conversation, we explore the strategic shifts, collaborative efforts, and technological innovations that are pushing the boundaries of quantum computing closer to building scalable, million-qubit systems. This episode was made with support form The American Physical Society and Quantum Machines, Inc. (BTW I know I said episode 49 in the intro to this episode, I noticed it too late to fix without a further delay in posting the interview!)

Key Highlights

• Emerging from Stealth Mode & Million-Qubit System Paper:
  • Discussion on QoLab’s transition from stealth mode and their comprehensive paper on building scalable million-qubit systems.
  • Focus on a systematic approach covering the entire stack.
• Collaboration with Semiconductor Companies:
  • Unique business model emphasizing collaboration with semiconductor companies to leverage external expertise.
  • Comparison with bigger players like Google, who can fund the entire stack internally.
• Innovative Technological Approaches:
  • Integration of wafer-scale technology and advanced semiconductor manufacturing processes.
  • Emphasis on adjustable qubits and adjustable couplers for optimizing control and scalability.
• Scaling Challenges and Solutions:
  • Strategies for achieving scale, including using large dilution refrigerators and exploring optical communication for modular design.
  • Plans to address error correction and wiring challenges using brute force scaling and advanced materials.
• Future Vision and Speeding Up Development:
  • QoLab’s goal to significantly accelerate the timeline toward achieving a million-qubit system.
  • Insight into collaborations with HP Enterprises, NVIDIA, Quantum Machines, and others to combine expertise in hardware and software.
• Research Papers Mentioned in this Episode:
  • Position paper on building scalable million-qubit systems 

In this episode of The New Quantum Era podcast, your host Sebastian Hassinger interviews two of the field's most well-known figures, John Preskill and Rob Schoelkopf, about the transition of quantum computing into a new phase that John is calling "megaquop," which stands for "a million quantum operations." Our conversation delves into what this new phase entails, the challenges and opportunities it presents, and the innovative approaches being explored to make quantum computing perform better and become more useful. This episode was made with the kind support of the American Physical Society and Quantum Circuits, Inc. Here’s what you can expect from this insightful discussion:

• Introduction of the Megaquop Era: John explains the transition from the NISQ era to the megaquop era, emphasizing the need for quantum error correction and the goal of achieving computations with around a million operations.
• Quantum Error Correction: Both John and Rob discuss the importance of quantum error correction, the challenges involved, and the innovative approaches being taken, such as dual rail and cat qubits.
• Superconducting Qubits and Dual Rail Approach: Rob shares insights into Quantum Circuits' work on dual rail superconducting qubits, which aim to make error correction more efficient by detecting erasure errors.
• Scientific and Practical Implications: The conversation touches on the scientific value of current quantum devices and the potential applications and discoveries that could emerge from the megaquop era.
• Future Directions and Challenges: The discussion also covers the future of quantum computing, including the need for better connectivity and the challenges of scaling up quantum devices.

Mentioned in this Episode:

• Beyond NISQ: The Megaquop Machine: John Preskill's paper adapting his keynote from Q2B Silicon Valley 2024
• Quantum Circuits, Inc.: Rob's company, which is working on dual rail superconducting qubits.

In this episode of The New Quantum Era podcast, host Sebastian Hassinger speaks with Steve Girvin, professor of physics at Yale University, about quantum memory - a critical but often overlooked component of quantum computing architecture. This episode was created with support from the American Physical Society and Quantum Circuits, Inc.

Episode Highlights

• Introduction to Quantum Memory: Steve explains that quantum memory is essential for quantum computers, similar to how RAM functions in classical computers. It serves as intermediate storage while the CPU works on other data.
• Coherence Challenges: Quantum bits (qubits) struggle to faithfully hold information for extended periods. Quantum memory faces both bit flips (like classical computers) and phase flips (unique to quantum systems).
• The Fundamental Theorem: Steve notes there’s “no such thing as too much coherence” in quantum computing - longer coherence times are always beneficial.
• Quantum Random Access Memory (QRAM): Unlike classical RAM, QRAM can handle quantum superpositions, allowing it to process multiple addresses simultaneously and create entangled states of addresses and their associated data.
• QRAM Applications: Quantum memory enables state preparation, construction of oracles, and processing of big data in quantum algorithms for machine learning and linear algebra.
• Tree Architecture: QRAM is structured like an upside-down binary tree with routers at each node. The “bucket brigade” approach guides quantum bits through the tree to retrieve data.
• Error Resilience: Surprisingly, the error situation in QRAM is less catastrophic than initially feared. With a million leaf nodes and 0.1% error rate per component, only about 1,000 errors would occur, but the shallow circuit depth (only requiring n hops for n address bits) makes the system more resilient.
• Dual-Rail Approach: Recent work by Danny Weiss demonstrates using dual resonator (dual-rail) qubits where a microwave photon exists in superposition between two boxes, achieving 99.9% fidelity for each hop in the tree.
• Historical Context: Steve draws parallels to early classical computing memory systems developed by von Neumann at Princeton’s IAS, including mercury delay line memory and early fault tolerance concepts.
• Future Outlook: While building quantum memory presents significant challenges, Steve remains optimistic about progress, noting that improving base qubit quality first and then scaling is their preferred approach.

Key Concepts

• Quantum Memory: Storage for quantum information that maintains coherence
• QRAM (Quantum Random Access Memory): Architecture that allows quantum superpositions of addresses to access corresponding data
• Coherence Time: How long a qubit can maintain its quantum state
• Bucket Brigade: Method for routing quantum information through a tree structure
• Dual-Rail Qubits: Encoding quantum information in the presence of a photon in one of two resonators

References

• Weiss, D.K., Puri, S., Girvin, S.M. (2024). “Quantum random access memory architectures using superconducting cavities.” arXiv:2310.08288
• Xu, S., Hann, C.T., Foxman, B., Girvin, S.M., Ding, Y. (2023). “Systems Architecture for Quantum Random Access Memory.” arXiv:2306.03242
• Brock, B., et al. (2024). “Quantum Error Correction of Qudits Beyond Break-even.” arXiv:2409.15065

In this episode of The New Quantum Era, host Sebastian Hassinger interviews Professor Will Oliver from MIT about the advancements in fluxonium qubits. The discussion delves into the unique features of fluxonium qubits compared to traditional transmon qubits, highlighting their potential for high fidelity operations and scalability. Oliver shares insights from recent experiments at MIT, where his team achieved nearly five nines fidelity in single-qubit gates, and discusses how these qubits could be scaled up for larger quantum computing architectures through innovative control systems.

Major Points Covered:

• Fluxonium vs. Transmon Qubits: Fluxonium qubits have a double-well potential, unlike the harmonic oscillator-like potential of transmon qubits. This design allows for high anharmonicity, which is beneficial for reducing leakage to higher energy levels during operations.
• High Fidelity Operations: The MIT team achieved high fidelity in both single and two-qubit gates using fluxonium qubits. For single qubits, they reached nearly five nines fidelity, and for two-qubit gates, they achieved fidelities around 99.92%.
• Scalability and Cost Reduction: Fluxonium qubits operate at lower frequencies, which could enable the integration of control electronics at cryogenic temperatures, reducing costs and increasing scalability. This approach is being developed by Atlantic Quantum, a startup spun out of Oliver's research group
• Future Directions: The goal is to implement surface code error correction with fluxonium qubits, which could lead to efficient production of logical qubits due to their high fidelity operations

This episode brought to you with support from APS and from Quantum Machines, a big thank you to both organizations!