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Nature Physics, Published online: 16 January 2024; doi:10.1038/s41567-023-02356-1

Never write off writing

Nature Physics, Published online: 16 January 2024; doi:10.1038/s41567-023-02373-0

A tiny escape

Nature Physics, Published online: 16 January 2024; doi:10.1038/s41567-023-02327-6

Bilayer graphene is known to host states where interactions dominate the electronic behaviour. Now, transport measurements show that this is also true for trilayer graphene and give evidence for ferroelectric states and states with high Chern number.

Nature Physics, Published online: 16 January 2024; doi:10.1038/s41567-023-02326-7

External driving of qubits can exploit their nonlinearity to generate different forms of interqubit interactions, broadening the capabilities of the platform.

Nature Physics, Published online: 16 January 2024; doi:10.1038/s41567-023-02325-8

Large quantum computers will require error correcting codes, but most proposals have prohibitive requirements for overheads in the number of qubits, processing time or both. A way to combine smaller codes now gives a much more efficient protocol.

Computer Security: Hits are coming closer

Like it or not, the cyber realm is unfortunately developing alongside the physical world. While in the real world, conflicts tragically dominate world politics, the usual commercial cyber-attackers have increased their attacks, too. And, unlike in the past, the research and education (R&E) sector is no longer spared.

Until recently, universities had been attacked only very occasionally. One of the last in this sad line-up was the University of Michigan. But the last year has also seen major attacks against accelerators and telescopes ─ as collateral damage and as the attackers’ main focus, respectively. What we feared in the past has become reality: where there is operational value, there is a business opportunity for malicious evildoers to extract money ─ and this applies to the R&E community as well. To “ransom” the operator, threaten operations, stop production and cause damage.

Over the past 12 months, the CERN Computer Security team has tirelessly helped dozens of universities worldwide to protect themselves against such “ransomware” attacks (see our monthly security reports) and improve their defences, as well as providing training, tipping them off to imminent danger where our threat intel permits and assisting them in incident response when it was too late and damage had been done. Similarly, the base question is not “if” but “when” CERN will be subject to a ransomware attack. The three mantras of ransomware defence are “Don’t get it”, “Don’t pay” and have all-encompassing, complete and thoroughly tested back-ups in place. While CERN has taken a firm position on the second mantra (incidentally, governments are increasingly prohibiting ransom payments), and the IT department, in collaboration with many stakeholders in the Organization, is hard at work on the third, the first mantra – raising our defences – is the hardest one. Many projects are already under way and we’re not done yet:

• 2024 will see an even more all-encompassing roll-out of 2-factor protection, in particular to our user community and to holders of so-called “secondary” accounts. It will eventually also cover LXPLUS and the CERN Windows terminal servers.
• The “new” anti-malware solution will finally be deployed to all CERN/centrally managed Windows PCs and we will investigate whether this protective means can also be forced onto any other Windows laptop or Macbook purchased and owned by the Organization.
• Vulnerability scanning and penetration testing against CERN’s internet presence is currently being tendered and will start in early 2024 (the owners of vulnerable websites and web servers may possibly be required to contribute to the cost).
• Together with HR’s Learning and Development group, we will expand CERN’s training catalogue and offer dedicated hands-on courses on secure programming and software development, as well as IT operations.
• In parallel, Gitlab security scanning may make it into your pipelines and into your choice of virtual machines and containers in order to reduce the risk through the “software supply chain”.
• Our Security Operations Centre will extend its remit to cover even more data sources, enabling us to monitor more network segments than ever before, as well as our main cloud-based services (such as Google and Microsoft).
• Finally, CERN recently concluded an external audit on “cyber security” and its findings and resulting recommendations will be addressed in the course of 2024 (more on that in a future Bulletin article).

In any case, ransomware hits are coming closer. Unlike some of our unfortunate partner universities and some astronomy experiments and particle accelerators, CERN has not been hit yet. Yet! And we hope to keep it that way. Cybersecurity is a permanent marathon: our work will never be done. But for this race, we appreciate (and need!) your help in securing the Organization. As “sec_irty” is not complete without “u”!!! Let’s have a (more) peaceful 2024.

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Do you want to learn more about computer security incidents and issues at CERN? Follow our Monthly Report. For further information, questions or help, check our website or contact us at Computer.Security@cern.ch.

In case you missed it in December, the talk "CERN Computer Security: Abuse, Blunder and Fun" will be repeated on 30 January at 11 h in the Council Chamber. More information on Indico: https://indico.cern.ch/event/1365440/ anschaef Mon, 01/15/2024 - 11:48 Byline Computer Security team Publication Date Mon, 01/15/2024 - 11:45

Nature Physics, Published online: 15 January 2024; doi:10.1038/s41567-023-02343-6

Optical atomic clocks are extremely accurate sensors despite the poor use of their resources. A parallel quantum control approach might help to optimize the resources of optical atomic clocks, which could lead to an exponential improvement in their performance.

Nature Physics, Published online: 15 January 2024; doi:10.1038/s41567-023-02322-x

Quantum-correlated photons typically characterize strongly nonlinear quantum emitters. A two-photon correlation spectroscopy method now provides a powerful probe of weakly nonlinear many-body quantum systems.

Nature Physics, Published online: 15 January 2024; doi:10.1038/s41567-023-02321-y

Quantum coherence is hard to maintain in solid-state systems, as interactions usually lead to fast dephasing. Exploiting disorder effects and interactions, highly coherent two-level systems have now been realized in a rare-earth insulator compound.

Nature Physics, Published online: 15 January 2024; doi:10.1038/s41567-023-02323-w

Addressing optical transitions at the level of a single site is crucial to unlock the potential of quantum computers and atomic clocks. A scheme based on atom rearrangement now demonstrates such control with demonstrable metrological benefits.

Nature Physics, Published online: 12 January 2024; doi:10.1038/s41567-023-02331-w

Precise frequencies of nearly forbidden transitions have been ascertained in the simplest molecule, the molecular hydrogen ion. This work offers a new perspective on precision measurements and fundamental physical tests with molecular spectroscopy.

Nature Physics, Published online: 12 January 2024; doi:10.1038/s41567-023-02318-7

Magnets with frustrated interactions are predicted to form quantum entangled states that feature measurable plateaus in their magnetization. Evidence for one of these plateau phases has now been found in a kagome lattice antiferromagnet.

Nature Physics, Published online: 12 January 2024; doi:10.1038/s41567-023-02320-z

Vibrational laser spectroscopy of the molecular hydrogen ion $${\rm{H}}_{2}^{+}$$ H 2 + offers new prospects for fundamental physics studies.

LHCb experiment releases all of its Run 1 proton–proton data

At the end of December 2023, the LHCb experiment released all its data from Run 1 of the Large Hadron Collider. This data, collected by the experiment in 2011 and 2012, contains approximately 800 terabytes of information obtained from proton–proton collisions. The data has been made available in a pre-filtered format, suitable for a wide range of physics studies for research and education purposes. 

LHCb data across Runs 1 and 2 has already been used for over 700 scientific publications, including numerous significant findings. All results from the collaboration have already been made publicly accessible in open-access papers and the numerical results from the graphs can be consulted in the HEPData database. With the new release, the data used by the researchers to produce these results is now accessible. The data has been released in the framework of CERN’s Open Data Policy, which reflects values that have been enshrined in the CERN Convention for more than sixty years and applies to all of CERN’s activities.

The collaboration has pre-processed the data by reconstructing experimental signatures, such as the trajectories of charged particles, from the raw information delivered by the complex detector system. The data is filtered, classified according to a large number of processes and decays, and made available in the same format that is used internally by LHCb physicists. The data can be downloaded from the CERN Open Data portal.

To aid the user’s understanding, the samples come with extensive documentation and metadata, as well as a glossary explaining several hundred specialised terms used in the pre-processing. The data can be analysed using dedicated LHCb algorithms, which are available as open-source software.

All data sets have digital identifiers (DOIs) for reference and citation. The experiment also welcomes feedback on how the data is used and invites users to discuss and post questions in the CERN Open Data Forum.

ndinmore Thu, 01/11/2024 - 11:28 Byline LHCb collaboration Publication Date Thu, 01/11/2024 - 11:21

Nature Physics, Published online: 11 January 2024; doi:10.1038/s41567-023-02317-8

In its superconducting state, MoTe2 displays oscillations arising from an edge supercurrent, and when it is near niobium, there is an incompatibility between electron pairs diffusing from niobium and the pairs intrinsic to MoTe2. Insight into this competition between pairs is obtained by monitoring the noise spectrum of the MoTe2 supercurrent oscillations.

Nature Physics, Published online: 11 January 2024; doi:10.1038/s41567-023-02310-1

Noise is a fundamental obstacle to the stability of atomic optical clocks. An experiment now realizes the design of a spin-squeezed clock that improves interrogation times and enables direct comparisons of performance between different clocks.

Nature Physics, Published online: 11 January 2024; doi:10.1038/s41567-023-02316-9

How superconducting states with different order parameter symmetries can interact with each other is not well understood. Now, the edge mode of a Weyl superconductor serves as a probe for competing condensates.

Nature Physics, Published online: 10 January 2024; doi:10.1038/s41567-023-02268-0

Predicting the large-scale behaviour of complex systems is challenging because of their underlying nonlinear dynamics. Theoretical evidence now verifies that many complex systems can be simplified and still provide an insightful description of the phenomena of interest.

Nature Physics, Published online: 10 January 2024; doi:10.1038/s41567-023-02312-z

Realizing robust ferromagnetic order in two dimensions is challenging as an underlying crystalline framework is normally required. Now room-temperature ferromagnetism is demonstrated in a two-dimensional honeycomb self-assembly of confined molecules.

Nature Physics, Published online: 10 January 2024; doi:10.1038/s41567-023-02303-0

Although using low-rank matrices is the go-to approach to model the dynamics of complex systems, its validity remains formally unconfirmed. An analysis of random networks and real-world data now sheds light on this low-rank hypothesis and its implications.