Wednesday, January 1, 2020

What was the greatest discovery of the past decade?

To my readers my best wishes for the New Year and the new decade!

It is worth reflecting on what has been achieved in condensed matter and chemical physics over the past decade. Which discovery or achievement would you rate as the most exciting, surprising, or significant?

To benchmark things, this is what I would say about previous decades, with regard to hard condensed matter, with a personal bias towards strongly correlated electron systems.

1970s: scaling and the renormalisation group

1980s: quantum Hall effects, cuprate superconductivity, heavy fermions, scanning tunneling microscopy (STM)

1990s: Dynamical Mean-Field Theory (DMFT), Kondo effect in quantum dots, superconducting qubits, (Angle-Resolved PhotoElectron Spectroscopy) ARPES advances, DMRG

2000s: iron-based superconductors, graphene, DMFT+DFT, topological insulators

2010s: ?

To be honest, I am worried that with each decade the discoveries are somewhat less exciting or significant. On the other hand, incremental advances, particularly steady ones over several decades should not be looked down on. An example is computational electronic structure methods and increases in the energy and momentum resolution associated with inelastic neutron scattering spectroscopy and ARPES.

What would you nominate for the past decade?

5 comments:

  1. 2010?



    https://backreaction.blogspot.com/2019/12/how-scientists-can-avoid-cognitive-bias.html



    Three major points for 2010? from the above web site by SHossenfelder.



    1) Changing area of research



    "For example, it is presently very difficult for a scientist to change their research topic, because getting a research grant requires that you document expertise. Likewise, no one will hire you to work on a topic you do not already have experience with. "



    2) Loss aversion,

    Take for example loss aversion. This is more commonly known as “throwing good money after bad”. It means that if we have invested time or money into something, we are reluctant to let go of it and continue to invest in it even if it no longer makes sense, because getting out would mean admitting to ourselves that we made a mistake. Loss aversion is one of the reasons scientists continue to work on research agendas that have long stopped being promising.



    3) Group think



    But the most problematic cognitive bias in science is social reinforcement, also known as group think. This is what happens in almost closed, likeminded, communities, if you have people reassuring each other that they are doing the right thing. They will develop a common narrative that is overly optimistic about their own research, and they will dismiss opinions from people outside their own community. Group think makes it basically impossible for researchers to identify their own mistakes and therefore stands in the way of the self-correction that is so essential for science.



    The third is rampant in all science and engineering and will lead low critical thinking and incremental work.



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  2. I'd think magic angles in graphene is a major discovery, irrespective of what use it is

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  3. Older discoveries may look more important because they have had more time to make an impact.

    Major discoveries of the last 10 years:

    1) Van der Waals materials: we can grow layers of meta-materials without worrying about epitaxial grow and they DO have non-trivial properties (emergent superconductivity in twisted bilayer graphene and others). This, together with the "cambric" explosion of new 2D materials (superconductors, ferromagnets, antiferromagnets, spin-valley coupled semiconductors) opens a huge area for new discoveries.

    2) The realization of Topological superconductivity in artificial nanostructures (even if you don't believe in topological qubits)

    3) Noisy Intermediate Scale Quantum computers (and their application for quantum simulation in a not-distant future)

    4) Large scale manipulation of thousands of atoms on surfaces + on-surface synthesis: Feynman's plenty-of-room dreams are now real

    5) High Throughput + AI: too soon to judge, but if they ever deliver part of what they promise, they will be disruptive in computational material science.

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  4. Should we add visible-spectrum LEDs to this mix? Red in the 60s, green in the 70s, blue I believe in the 90s (though the Physics Nobel Prize was in 2014). The 20th/21st centuries' "light-bulb" innovation where condensed matter physics has made everyday life concretely better!

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  5. I would also add development of high-resolution time-resolved spectroscopy techniques (mostly experiment, but also theory: time-dependent DMFT etc) and maybe even the impressive advances in RIXS.

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