Stockholm university
Department of Physics

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Department of Physics

Quantum metric unveils defect freezing in non-Hermitian systems

The fundamental postulates of quantum mechanics rest upon the fact that the Hamiltonian, which quantifies the energy of the system, is given by a Hermitian operator. This means that the complex conjugate and transpose of the Hamiltonian should be equal to itself. Almost a century after the formulation of quantum mechanics, researchers are now trying to break free from this constraint — non-Hermitian Hamiltonians, which do not satisfy the aforementioned property, are now a new frontier of exploration in both theoretical and experimental physics. Paolo Hermignini is part of the project and is a Postdoctor in Condensed Matter and Quantum Optics at Fysikum.

Non-Hermitian Systems
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Department of Physics

Word and bit line operation of a 1x1 μm2 superconducting vortex-based memory

The third industrial “digital” revolution is on the way. The volume of digital information, the amount of large computation facilities and the related energy consumption are growing in an explosive manner. The notorious “memory wall” problem reveals ineffectiveness of the standard processor-centered computation for processing of big data volumes and actuates the necessity of both hardware and software development for new types of in-memory computation. Simultaneously, silicon-based electronics is approaching its limits. The large resistivity of nano-scale semiconductor transistors and interconnections impedes operation speed and causes severe heat management problems. Sustainability of the present digitalization trend requires radical innovative solutions.

Scanning electron image of a small vortex-based memory cell.
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Calendar

17 October

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19 October

Conference

Department of Physics

Welcome to OKC's 15th anniversary conference!

The Oskar Klein Centre is celebrating 15 years as a hub for physics research in Stockholm. To recognize this achievement, and also look towards the future, we are organizing a lively scientific conference covering topics in cosmology, astrophysics and particle physics.

Department of Physics

Welcome to OKC's 15th anniversary conference!

The Oskar Klein Centre is celebrating 15 years as a hub for physics research in Stockholm. To recognize this achievement, and also look towards the future, we are organizing a lively scientific conference covering topics in cosmology, astrophysics and particle physics.

Physics - Theme page