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Quantum Paper Club

Quantum Matter under the Microscope

Neutral atoms are nature’s perfect qubits: they are all identical, and our precise knowledge of their properties allows us to control them at will. Cooling and trapping many atoms offers the unique opportunity to experimentally address outstanding problems in many-body quantum physics. Quantum gas microscopy brings this effort to the ultimate level of single particle…

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Quantum Paper Club

Tensor Network Algorithms for Quantum Chemistry

High-accuracy quantum chemical calculations are commonly limited to relatively small molecules due to the exponential scaling of the computational cost with the number of involved particles. By leveraging powerful tensor decomposition-based approaches, tensor network algorithms are continuously expanding the scope of wave function-based molecular simulation methods. While tensor network-based methods such as the density matrix…

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Quantum Paper Club

Security Proof of QKD Protocols via Entropic Uncertainty Relations

The field of Quantum Key Distribution (QKD) has attracted a lot of attention as one of the quantum technologies that not only addresses one of the most pressing problems in secret communication, but has also shown promising progress on the implementation side. A major advantage of QKD protocols is their provable security. This talk will…

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Quantum Paper Club

Optical levitation on chip

Levitation in vacuum has evolved into a versatile technique which has already benefited diverse scientific directions, from force sensing and thermodynamics to material science and chemistry. It also holds great promises of advancing the study of quantum mechanics in the unexplored macroscopic regime. While most current levitation platforms are complex and bulky, miniaturization is sought…

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Quantum Paper Club

Engineering New Doppler Limits

When you want to trap neutral atoms in optical tweezers you better be cold. And when I say cold I don’t mean dilution fridge cold. I mean 10 times colder. To reach such temperatures we conventionally use laser cooling, which brings us to the doppler temperature proportional to the transition linewidth. But what if the…

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Quantum Paper Club

Entropy Spectroscopy of a Bilayer Graphene Quantum Dot

Bilayer graphene (BLG) has emerged as a promising platform for hosting qubits within 2D materials. By encapsulating it in a dielectric and applying gating techniques, one can electrostatically confine individual charge carriers, both electrons and holes, and thus obtain what is called a quantum dot (QD). Charge detection schemes allow us study the quantum properties…

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Quantum Paper Club

Soft information decoding: Are we overlooking measurement details in quantum error correction?

Quantum computers can provide asymptotically faster computation times than their classical counterparts in specific applications. However, to outperform the classical computers we have today, we need large-scale, fault-tolerant devices. Quantum error correction (QEC) is considered one of the most promising ways of achieving this milestone. However, much work is still needed to improve both the…

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Quantum Paper Club

Supersolidity in ultracold quantum gases: the simultaneous crystalline and superfluid nature of dipolar atoms

Quantum physics frequently gives rise to conceptual paradoxes that defy our classical intuition. In many-body quantum systems, interactions are key, especially when they dominate over kinetic energy. Their form and strength crucially define the existing strongly-correlated quantum phases of matter and dictate phenomena beyond the classical regime. Dipolar interactions, particularly relevant in strongly magnetic atoms,…

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Quantum Paper Club

Performance constraints of NISQ quantum algorithms and their mitigation with 3D-integrated superconducting quantum devices

In recent years, the excitement around NISQ algorithms has diminished, partly due to the performance limitations of existing quantum computers. Devices with more qubits and lower error rates are necessary to realize the potential of quantum computing. In the first half of this talk, I will illustrate these performance limitations with the example of the…

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Quantum Paper Club

Two-dimensional terahertz spectroscopy in complex matter systems

Two-dimensional terahertz spectroscopy (2DTS), a terahertz analogue of nuclear magnetic resonance, stands as a novel technique poised to address numerous open questions in complex condensed matter systems. The conventional theoretical framework, widely used for interpreting multidimensional spectra of discrete quantum-level systems, falls short in capturing the continua of collective excitations in strongly correlated materials, and…