Hall effect works with in-plane magnetic fields, Carnegie Mellon team shows

Overview

Updated 46 minutes ago

For 147 years, physicists relied on a simple rule: the Hall effect needs a magnetic field pointing straight at a material's surface. Carnegie Mellon researchers just showed that rule was wrong.

Their experiments detected a second Hall signal driven by an in-plane magnetic field in devices just a few atomic layers thick. A single sensor can now measure magnetic fields in multiple directions, something that previously required separate sensors.

Why it matters

A single ultra-thin sensor could soon replace the separate magnetic field detectors cars, phones, and medical devices rely on today.

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Key Indicators

147 years

Years the perpendicular-field assumption stood

Edwin Hall discovered the effect in 1879; Carnegie Mellon expanded it in 2026.

Magnetic field directions a single device can sense

One ultra-thin device measures both out-of-plane and in-plane field components.

Nature Materials

Peer-reviewed journal where the results were published

One of the leading journals in materials science and condensed matter physics.

Voices

Curated perspectives — historical figures and your fellow readers.

Ever wondered what historical figures would say about today's headlines?

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People Involved

Simranjeet Singh

Associate Professor of Physics, Carnegie Mellon University

Principal investigator leading the discovery

Shubhayu Chatterjee

Assistant Professor of Physics, Carnegie Mellon University

Developed the theoretical model explaining the effect

Jyoti Katoch

Associate Professor of Physics, Carnegie Mellon University

Fabricated the atomically thin devices

I-Hsuan Kao

Postdoctoral Researcher, Carnegie Mellon University

Co-first author, ran the measurements

Ravi Kumar Bandapelli

Postdoctoral Researcher, Carnegie Mellon University

Co-author, ran the measurements

Edwin Hall

Physicist, discovered the Hall effect

Historical figure (1855-1938)

Organizations Involved

Carnegie Mellon University

Private Research University

Site of the discovery

The university where the in-plane anomalous Hall effect was first demonstrated.

Nature Materials

Peer-Reviewed Scientific Journal

Publisher of the research

A leading peer-reviewed journal covering materials science and condensed matter physics.

Timeline

September 1879 September 2026

4 events Latest: 3 days ago

Tap a bar to jump to that date

September 2026
Discovery gains wide coverage
Latest Media

Wide coverage follows Carnegie Mellon's announcement of the in-plane Hall effect finding.
3 days ago
Carnegie Mellon issues press release
Announcement

Carnegie Mellon issues press release; ScienceDaily publishes the announcement.
5 days ago
August 2026
Nature Materials publishes the in-plane Hall effect paper
Publication

Carnegie Mellon team publishes paper on in-plane anomalous Hall effect in Nature Materials.
August 1st, 2026
September 1879
Hall discovers the Hall effect
Discovery

Edwin Hall discovers that a perpendicular magnetic field deflects current in a conductor.
September 1st, 1879

Historical Context

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

September 1879

Edwin Hall's Discovery (1879)

While a graduate student at Johns Hopkins University, Edwin Hall ran an experiment showing that a magnetic field perpendicular to a current-carrying conductor deflects moving charges, creating a measurable transverse voltage. He published the result later that year.

Then

The finding gave physicists a way to measure charge carrier density and sign in materials.

Now

The Hall effect became a standard tool in condensed matter physics and the basis for sensors used in cars, smartphones, and industrial equipment.

Why this matters now

This is the same effect the CMU team just extended. Hall's original geometry assumed perpendicular fields; the new work shows the effect also works with in-plane fields.

1980

Quantum Hall Effect (1980)

Klaus von Klitzing found that in a two-dimensional electron gas at very low temperatures and high magnetic fields, the Hall resistance becomes quantized in exact fractions. He won the 1985 Nobel Prize for the work.

Then

The effect led to a new international standard for electrical resistance.

Now

It spawned the field of topological physics and, later, the fractional quantum Hall effect, which remains an active research area.

Why this matters now

This earlier 'new direction' for the Hall effect shows how expanding a known phenomenon can produce both fundamental physics insights and practical metrology tools.

1988

Giant Magnetoresistance (1988)

Albert Fert in France and Peter Grünberg in Germany independently discovered that alternating ultra-thin magnetic and nonmagnetic layers change electrical resistance dramatically when exposed to magnetic fields. Both later shared the 2007 Nobel Prize in Physics.

Then

IBM built the first giant magnetoresistance (GMR) read heads for hard drives within about a decade.

Now

GMR and related spintronics technology enabled the terabyte-scale hard drives that made modern data storage possible.

Why this matters now

Like the CMU discovery, GMR began as a thin-film physics finding in a lab and took years to reach commercial products. It shows the typical path from fundamental discovery to application.