In this episode, Sebastian Hassinger sits down with Dr. Liang Jiang from the University of Chicago to explore the exciting intersection of quantum error correction theory and practical implementation. Dr. Jiang discusses his group's work on hardware-efficient quantum error correction, the recent breakthroughs in demonstrating error correction thresholds, and the future of fault-tolerant quantum computing.

Key Topics Covered

Current State of Quantum Error Correction

• Recent milestone achievements including Google's surface code experiment and AWS's bosonic code demonstrations
• The transition from purely theoretical work to practical implementations on real hardware
• Hardware platforms showing high fidelity: superconducting qubits, trapped ions, and cold atoms

Hardware-Efficient Approaches

• Bosonic Error Correction: Using single harmonic oscillators to correct loss errors, demonstrated at Yale and AWS
• Surface Codes: Google's achievement of going beyond breakeven point for quantum memory
• QLDPC Codes: Collaboration with IBM and neutral atom array experiments, particularly Michel Lukin's group at Harvard

Fault-Tolerant Gate Implementation

• Challenges of implementing universal computation with error-corrected logical qubits
• Magic State Injection: Preparing resource quantum states and teleporting them into circuits
• Code Switching: Switching between different error correcting codes to achieve universal gate sets
• The Eastin-Knill no-go theorem and methods to overcome it

Programming Abstraction Layers

• Evolution toward higher-level programming abstractions similar to classical computing
• Efficient compilation of quantum circuits using discrete fault-tolerant gate sets
• Memory Operations: Teleporting gates into quantum memory rather than extracting qubits

Quantum Communication and Networking

Channel Capacity and GKP Codes

• Application of Gottesman-Kitaev-Preskill (GKP) codes for achieving channel capacity in lossy channels
• Recent experimental demonstrations in trapped ions and superconducting qubits showing breakeven performance

Microwave-to-Optical Transduction

• Critical challenge for connecting quantum devices across different frequency domains
• Recent progress in demonstrating quantum channels between microwave and optical modes
• Applications for both quantum networking and modular quantum computing architectures

Advanced Applications

Quantum Sensing with Error Correction

• Research by Dr. Jiang's former student Sisi Zhou addressing John Preskill's 20-year-old question
• Necessary and sufficient conditions for error correction to help quantum sensing
• Applications to gravitational wave detection and dark matter searches

Algorithmic Quantum Metrology

• Collaboration with MIT researchers on combining global search algorithms with quantum sensors
• Potential for quantum advantage in processing quantum signals from quantum sensors

Future Directions

Distributed Quantum Computing

• Modular architecture with specialized components: memory, processors, and interfaces
• Scaling challenges requiring interconnects between different quantum devices
• System-level thinking about quantum computer architecture

Application-Specific Error Correction

• Tailoring error correction schemes for specific algorithms and applications
• Co-design approach considering hardware capabilities and application requirements

Key Insights

• Theory-Experiment Collaboration: The importance of close collaboration between theorists and experimentalists to understand real-world error models
• Hardware Efficiency: Moving beyond generic error correction to platform-specific and application-specific approaches
• Temporal Considerations: The need for not just hardware efficiency but also time efficiency in quantum operations
• Abstraction Evolution: The inevitable move toward higher-level programming abstractions as fault-tolerant quantum computing matures

Notable Quotes

"We want to do hardware efficient quantum error correction... given qubits are still very precious resource."

"Quantum computers are really good at processing quantum signals. Where does the quantum signal come from? Quantum sensor is definitely a very promising source."

About the Guest:
Dr. Liang Jiang leads a research group at the University of Chicago focused on the practical implementation of quantum error correction and fault-tolerant quantum computing. His work spans multiple quantum platforms and emphasizes the co-design of hardware and error correction schemes.

About The New Quantum Era:
The New Quantum Era is hosted by Sebastian Hassinger and features in-depth conversations with leading researchers and practitioners in quantum computing, exploring the latest developments and future prospects in the field.

In this episode of The New Quantum Era, your host, Sebastian Hassinger sits down with Dr. Yvonne Gao, a leading experimental physicist specializing in superconducting devices and quantum cavities. Recorded at the American Physical Society's Global Summit, the conversation explores the intersection of curiosity-driven research and technological advancement in quantum physics.

Key Topics Discussed

1. Research Focus: Quantum Cavities and Superposition

• Dr. Gao shares her team's work on using cavities (harmonic oscillators) coupled with a single qubit to probe fundamental quantum effects.
• The experiments focus on quantum superposition and entanglement using minimal hardware—just one qubit and one cavity—eschewing the race for more qubits in favor of deeper scientific insights.
• Discussion of "cat states" as iconic demonstrations of quantum superposition, and how their properties can be engineered for robustness and sensitivity without specialized hardware.

2. Experimental Innovation

• The team investigates loss mechanisms in cavity-based quantum states and explores ways to make these states more resilient through state engineering rather than hardware changes.
• Dr. Gao describes using standard, "vanilla" qubits and cavities, making their techniques accessible to other labs.

3. Fundamental Questions and Quantum Playground

• Dr. Gao emphasizes the value of the circuit QED platform as a "playground" for exploring quantum phenomena, particularly entanglement and its quantification in real hardware.
• The challenge of visualizing and intuitively understanding quantum phenomena is highlighted, with experiments designed to make abstract concepts more tangible.

4. Device Fabrication and Advancements

• Dr. Gao's lab at NUS has developed in-house fabrication capabilities, gradually building up expertise and infrastructure.
• The field is witnessing rapid improvements in device performance, driven by advances in materials science and process integration.

5. Multipartite Entanglement and Future Directions

• Plans for multi-cavity devices: Moving from single and two-cavity systems to three, enabling the study of tripartite entanglement and richer quantum dynamics.
• The potential for these systems to serve as both research tools and pedagogical aids, demonstrating quantum strangeness in a hands-on way.

6. Synergy Between Science and Technology

• The conversation explores the unique moment in quantum research where fundamental science and technological objectives are closely aligned.
• Knowledge flows both ways: curiosity-driven experiments inform processor design, while industrial advances in fabrication and control benefit academic labs.

7. The "Perfect Quantum Lab" Thought Experiment

• Dr. Gao shares her wish list for a hypothetical, fault-tolerant quantum computer: to directly observe textbook quantum phenomena and simulate complex quantum behaviors in a tangible way.

Memorable Quotes

Find this and other episodes at New Quantum Era’s website or wherever you get your podcasts. If you enjoyed the episode, please subscribe and share with your quantum-curious friends!

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.