The journey to modern quantum computing represents one of science’s most fascinating frontiers, beginning with Max Planck’s revolutionary quantum theory in 1900 and advancing through decades of groundbreaking discoveries. From Bohr’s quantum atom model to Feynman’s visionary proposal for quantum computers, each milestone built upon the last, gradually transforming theoretical quantum mechanics into practical computing technology. Pasqal stands at the culmination of this remarkable scientific journey, particularly the transformative advancements in neutral atom quantum computing pioneered at Institut d’Optique. Our technology directly harnesses the quantum principles discovered by these visionaries, using precisely controlled arrays of neutral atoms to create powerful quantum processors capable of solving previously intractable problems. This timeline showcases the foundational discoveries that made our quantum computing approach possible and highlights Pasqal’s role in bringing this revolutionary technology from laboratory experiments to real-world applications.
Quantum Theory Foundations
1900 : Planck’s Quantum Revolution
Max Planck discovered that energy is emitted and absorbed in discrete packets called “quanta,” solving the blackbody radiation problem that puzzled physicists. This revolutionary insight marked the birth of quantum theory, challenging classical physics by introducing discreteness at the atomic scale.
1913 : Bohr’s Quantum Atom
Niels Bohr proposed that electrons can only exist in specific, quantized orbital energy levels rather than orbiting continuously around the nucleus. His model explained why atoms emit and absorb light at specific wavelengths, as electrons could only jump between these discrete energy states, releasing or absorbing photons with precise energies.
1925-1926 : Birth of Quantum Mechanics
Werner Heisenberg developed matrix mechanics while Erwin Schrödinger formulated wave mechanics, two mathematical frameworks later proven to be equivalent descriptions of quantum phenomena. These formalisms established modern quantum mechanics, describing a probabilistic universe where particles exhibit wave-particle duality and follow the uncertainty principle, creating the theoretical foundation for quantum computing.
Theoretical Groundwork
1935 : The Einstein-Podolsky-Rosen Paradox
Einstein, Podolsky, and Rosen published a thought experiment suggesting quantum mechanics was incomplete because it allowed for “spooky action at a distance” between entangled particles. Instead of disproving quantum theory as intended, their paper inadvertently highlighted the profound phenomenon of quantum entanglement, which would later become a cornerstone resource for quantum computing.
1939 : Rabi’s Quantum Control Breakthrough
Isidor Rabi demonstrated nuclear magnetic resonance (NMR), showing how atomic nuclei in a magnetic field can be flipped between quantum states using radio waves. This groundbreaking technique provided the first practical method for controlling quantum states with electromagnetic radiation, establishing principles that would evolve into the precise qubit manipulation methods used in modern quantum computers.
Quantum Control Begins
1952 : Quantum Measurement Milestone
Felix Bloch and Edward Mills Purcell received the Nobel Prize for developing precise methods to measure the magnetic properties of atomic nuclei through nuclear magnetic resonance. Their techniques allowed scientists to observe quantum properties of atoms with unprecedented accuracy, establishing experimental tools that would become essential for studying and manipulating quantum systems.
1965 : Bell’s Quantum Challenge
John Bell formulated a mathematical inequality that could experimentally test whether quantum entanglement was real or if “hidden variables” could explain quantum effects. Bell’s theorem transformed a philosophical debate into a testable scientific question, providing the framework for experiments that would eventually confirm entanglement’s non-local nature and challenge our fundamental understanding of reality.
1972 : Aspect’s Quantum Journey Begins
Alain Aspect started his pioneering work on experimental tests of quantum mechanics that would eventually provide definitive evidence for quantum entanglement. His research journey would culminate in the groundbreaking experiments of the early 1980s that would conclusively demonstrate the reality of “spooky action at a distance,” confirming one of quantum mechanics’ most counterintuitive predictions and establishing principles crucial for quantum computing.
Quantum Computing Emerges
1981 : Feynman’s Quantum Vision
Richard Feynman proposed that only quantum computers could efficiently simulate quantum physics problems that classical computers struggle with. His insight recognized that quantum systems could potentially solve certain problems exponentially faster than classical computers, establishing the theoretical motivation for developing quantum computing technology.
1983 : Aspect Confirms Quantum Entanglement
Alain Aspect conducted experiments that confirmed Bell’s inequality violations, proving that quantum entanglement was a real phenomenon where measuring one particle instantly affects its entangled partner regardless of distance. His work definitively demonstrated that quantum mechanics’ strange predictions were correct, closing loopholes in previous experiments and establishing entanglement as a real phenomenon that could be harnessed for computation.
1985 : Deutsch’s Universal Quantum Computer
David Deutsch described the first theoretical model of a universal quantum computer, showing how quantum gates could perform any possible quantum computation. His work extended the concept of universal computation to the quantum realm, establishing the theoretical possibility of quantum computers that could solve problems beyond the reach of any classical computer.
1994 : Shor’s Algorithm Breakthrough
Peter Shor developed an algorithm showing that quantum computers could factor large numbers exponentially faster than the best known classical algorithms. This discovery had profound implications for cryptography and provided the first clear example of a practical problem where quantum computers would have a dramatic advantage, accelerating interest and investment in quantum computing research.
1995 : First Quantum Logic Gate
Researchers from the National Institute of Standards and Technology (NIST) demonstrated the first controlled-NOT quantum gate, a fundamental building block for quantum computation that allows for entanglement between qubits. This experimental milestone moved quantum computing from theoretical concept to physical reality, proving that the basic operations required for quantum computation were physically possible and setting the stage for more complex quantum circuits.
Neutral Atom Quantum Computing Takes Shape
2001 : Single Atom Optical Trapping
Scientists, including current CEO of Pasqal Georges-Olivier Reymond, demonstrated the ability to trap individual neutral atoms using tightly focused laser beams called optical tweezers, a critical step toward atom-by-atom quantum control. This technical achievement allowed researchers to isolate and manipulate single quantum particles with unprecedented precision, establishing a promising platform for quantum information processing that would later become the foundation of Pasqal’s technology.
2009 : Entanglement of two individual neutral atoms using Rydberg blockade
Wilk, Gaëtan and the team led by Antoine Browaeys achieved the first entanglement of two individual neutral atoms using the Rydberg blockade effect, published in Nature Physics. This groundbreaking experiment demonstrated that neutral atoms could be precisely manipulated to create quantum entanglement—a critical resource for quantum computing—through controlled excitation to Rydberg states. The achievement marked a pivotal moment in neutral atom quantum computing, proving that these systems could perform the fundamental quantum operations necessary for information processing while maintaining excellent coherence properties.
Path to Pasqal
2016: High-Fidelity Neutral Atom Control
Thierry Lahaye and Antoine Browaeys demonstrated high-fidelity quantum operations with neutral atoms, achieving precise quantum state manipulation and measurement with error rates low enough for practical quantum computing. These improvements in quantum gate fidelity and control techniques established neutral atoms as a leading contender for quantum computing platforms, proving that the approach could meet the stringent requirements for quantum error correction and computation.
2018: Institut d’Optique Breakthrough
Antoine Browaeys, Thierry Lahaye, and their team at Institut d’Optique demonstrated unprecedented control of large arrays of neutral atoms with programmable interactions, showing their viability for quantum simulation and computing. Their groundbreaking work proved that neutral atom platforms could perform complex quantum operations with high precision while maintaining excellent scalability, creating the scientific foundation for Pasqal’s quantum computing approach.
2019: Pasqal’s Founding
Pasqal was established to commercialize neutral atom quantum computing technology, building directly on the pioneering research at Institut d’Optique. The company brought together world-class expertise in quantum physics and engineering to transform groundbreaking laboratory demonstrations into practical quantum computing systems, beginning the journey from scientific discovery to commercial quantum technology.
