From real-time measurements to engineered quantum systems

In this interview, Professor Charles Marcus discusses his current research across labs in Seattle and Copenhagen, focusing on the creation of synthetic quantum matter by engineering structure in both space and time dimensions. In space – via epitaxial growth (Z-direction) and in-plane lithography (X-Y), and in time – through controlled quantum measurements and real-time feedback. His work sits at the intersection of condensed matter physics and quantum information, probing how measurement itself becomes a tool for driving dynamics and inducing quantum phase transitions.

KEY TOPICS EXPLORED

• Synthetic Quantum Systems: Techniques for building systems from heterostructures and patterned superconducting/qubit arrays to explore emergent phenomena inaccessible in naturally occurring materials.
• Measurement-Induced Phase Transitions: An in-depth look at how frequent, projective measurements affect entanglement dynamics
in many-body systems, potentially driving new quantum phases.
• Conditional Feedback and Algorithmic Cooling: The role of using measurement outcomes to inform subsequent operations – connecting to quantum error correction, entropy reduction, and
the broader design of temporally structured quantum protocols.
• Partnership with Quantum Machines: A technical collaboration aimed
at enabling these feedback-rich experiments in practice, supportedby
an engineering team fluent in both hardware control and quantum theory.
• Return to Foundational Inquiry: A candid perspective on the field’s renewed attention to fundamental questions – where the aim is understanding, not just application.
• Diverse Research Environments: A cross-continental framework offering students and postdocs exposure to both American and European scientific cultures, methodologies, and infrastructure.

This conversation offers a technically rich, intellectually honest reflection on how quantum measurement – often seen as a passive process – can be used as an active axis in system design. Essential viewing for researchers engaged with quantum dynamics, measurement theory, and the experimental frontier of programmable many-body systems.