The quest to trap antimatter

Overview

CERN's BASE collaboration kept a single antiproton oscillating between quantum states for 50 seconds—long enough to create the world's first antimatter qubit. The breakthrough, published in Nature in July 2025, opens the door to measuring antiproton properties with 10 to 100 times more precision than before. That precision could answer a cosmic mystery: why the universe exists.

The Big Bang should have created equal amounts of matter and antimatter, which would have annihilated each other into pure energy. Instead, one particle in every billion survived—and that's everything we see. Finding even tiny differences between protons and antiprotons could explain this cosmic imbalance, cracking open one of physics' deepest puzzles.

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Key Indicators

50 sec

Antiproton Coherence Time

First coherent quantum transition ever observed in a free antimatter particle

100x

Precision Improvement

Expected increase in antiproton property measurement accuracy

1:1,000,000,000

Matter Survival Rate

Ratio of matter that survived Big Bang annihilation—the mystery driving this research

0.8 ppm

Current Measurement Precision

Magnetic moment comparison accuracy between protons and antiprotons (parts per million)

Voices

Curated perspectives — historical figures and your fellow readers.

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People Involved

Stefan Ulmer

Leading antimatter research at CERN and RIKEN

Paul Dirac

Deceased (predicted antimatter in 1928)

Andrei Sakharov

Deceased (proposed baryogenesis conditions in 1967)

Organizations Involved

BASE (Baryon Antibaryon Symmetry Experiment)

Particle physics experiment

Active at CERN's Antiproton Decelerator

International team comparing protons and antiprotons to find asymmetries that could explain why matter dominates the universe.

CERN Antiproton Decelerator

Particle Physics Facility

World's only source of low-energy antiprotons

The Antimatter Factory that produces and slows antiprotons for precision experiments.

ALPHA (Antihydrogen Laser Physics Apparatus)

Research Collaboration

Active at CERN

Collaboration studying antihydrogen atoms to test matter-antimatter symmetry and gravity.

RIKEN

Japanese Research Institute

Partnering with BASE collaboration

Japan's largest comprehensive research institution, hosting the Ulmer Fundamental Symmetries Laboratory.

Timeline

January 1928 July 2025

12 events Latest: July 23rd, 2025 · 10 months ago Showing 8 of 12

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July 2025
First Antimatter Qubit Created
Latest Breakthrough

BASE maintains single antiproton in coherent quantum superposition for 50 seconds, published in Nature. First coherent spectroscopy of free antimatter particle.
July 23rd, 2025
August 2024
Rapid Cooling Method Developed
Technique

BASE develops trap reducing antiproton cooling time from 15 hours to 8 minutes for faster, more precise measurements.
August 1st, 2024
September 2023
Antimatter Falls Down
Measurement

ALPHA-g collaboration publishes Nature paper showing antihydrogen falls under gravity like matter, ruling out repulsion theory.
September 27th, 2023
January 2021
Sympathetic Cooling Breakthrough
Technique

BASE demonstrates sympathetic cooling of protons, recognized as Physics World Top 10 Breakthrough of the Year.
January 1st, 2021
October 2017
350x Precision Leap
Measurement

BASE breaks own record with antiproton magnetic moment measurement at 0.8 parts per million—more precise than proton.
October 1st, 2017
August 2015
Most Precise CPT Test in Baryon Sector
Measurement

BASE publishes antiproton-to-proton charge-to-mass ratio measurement in Nature at 69 parts per trillion precision.
August 13th, 2015
June 2014
BASE Measures Proton Magnetic Moment
Measurement

BASE collaboration achieves first direct high-precision proton measurement at 3.3 parts per billion fractional precision.
June 1st, 2014
July 2000
Antimatter Factory Opens
Infrastructure

CERN's Antiproton Decelerator begins operations, providing low-energy antiprotons to multiple experiments.
July 1st, 2000
February 1997
CERN Approves Antiproton Decelerator
Infrastructure

CERN Council approves conversion of antiproton collector into dedicated antimatter factory.
February 1st, 1997
January 1967
Sakharov Conditions Published
Theoretical

Andrei Sakharov proposes three conditions necessary to explain matter-antimatter asymmetry, launching baryogenesis field.
January 1st, 1967
August 1932
First Antimatter Discovered
Experimental

Carl Anderson observes positron tracks in cloud chamber, confirming Dirac's prediction. Wins Nobel Prize in 1936.
August 2nd, 1932
January 1928
Dirac Predicts Antimatter
Theoretical

Paul Dirac's equation combining quantum theory and relativity predicts existence of antiparticles with opposite charge.
January 2nd, 1928

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Historical Context

3 moments from history that rhyme with this story — and how they unfolded.

1964-1980

Discovery of CP Violation (1964)

James Cronin and Val Fitch discovered that neutral kaons decay differently than their antimatter counterparts, violating charge-parity symmetry. This was the first experimental proof that nature's laws treat matter and antimatter differently. The discovery earned them the 1980 Nobel Prize and showed that asymmetry between matter and antimatter exists in nature.

Then

Shocked the physics community and validated the possibility that matter-antimatter asymmetry could be explained by fundamental laws, not just initial conditions.

Now

Became a cornerstone of modern cosmology, but the observed CP violation is far too small to explain the universe's matter dominance, driving searches for additional sources.

Why this matters now

BASE's precision measurements search for CP and CPT violations in baryons that could provide the missing explanation for why we exist.

1960s-2012

Higgs Boson Discovery (2012)

Peter Higgs and others predicted a field giving particles mass in the 1960s. CERN's Large Hadron Collider found the Higgs boson in 2012 after a decades-long search requiring unprecedented detector precision and data analysis. The discovery confirmed the Standard Model's final missing piece, earned Higgs and François Englert the 2013 Nobel Prize.

Then

Validated the Standard Model and demonstrated that massive, coordinated experiments can find predicted particles decades after theorists propose them.

Now

Completed the Standard Model but highlighted what it can't explain—including matter-antimatter asymmetry, dark matter, and dark energy.

Why this matters now

Like the Higgs search, BASE pursues a decades-long precision measurement program to test theoretical predictions. But where Higgs validated the Standard Model, BASE might break it.

1995-2025

Trapped Ion Quantum Computing (1990s-present)

Researchers developed techniques to trap individual ions with electromagnetic fields and manipulate their quantum states, achieving coherence times extending to hours. These systems became leading candidates for quantum computers due to their stability and precision control. Current record coherence times exceed 5,500 seconds for ytterbium ions.

Then

Demonstrated that quantum states can be maintained far longer than initially thought possible with proper isolation and control.

Now

Enabled both quantum computing development and ultra-precise measurements of fundamental physics, with trapped ion techniques now standard in metrology.

Why this matters now

BASE adapted trapped ion techniques for antiprotons, using Penning traps to create the antimatter qubit. The 50-second coherence time proves antimatter can be controlled with similar quantum precision.