@article{12154,
  abstract     = {We review our theoretical results of the sound propagation in two-dimensional (2D) systems of ultracold fermionic and bosonic atoms. In the superfluid phase, characterized by the spontaneous symmetry breaking of the U(1) symmetry, there is the coexistence of first and second sound. In the case of weakly-interacting repulsive bosons, we model the recent measurements of the sound velocities of 39K atoms in 2D obtained in the weakly-interacting regime and around the Berezinskii–Kosterlitz–Thouless (BKT) superfluid-to-normal transition temperature. In particular, we perform a quite accurate computation of the superfluid density and show that it is reasonably consistent with the experimental results. For superfluid attractive fermions, we calculate the first and second sound velocities across the whole BCS-BEC crossover. In the low-temperature regime, we reproduce the recent measurements of first-sound speed with 6Li atoms. We also predict that there is mixing between sound modes only in the finite-temperature BEC regime.},
  author       = {Salasnich, Luca and Cappellaro, Alberto and Furutani, Koichiro and Tononi, Andrea and Bighin, Giacomo},
  issn         = {2073-8994},
  journal      = {Symmetry},
  keywords     = {Physics and Astronomy (miscellaneous), General Mathematics, Chemistry (miscellaneous), Computer Science (miscellaneous)},
  number       = {10},
  publisher    = {MDPI},
  title        = {{First and second sound in two-dimensional bosonic and fermionic superfluids}},
  doi          = {10.3390/sym14102182},
  volume       = {14},
  year         = {2022},
}

@article{15265,
  abstract     = {The highly enhanced thermoelectric figure of merit, zT ≈ 2.6 at 573 K, obtained recently in Cd-doped polycrystalline AgSbTe2 by Roychowdhury et al. ( Science 2021, 371, 722) brings it to the forefront of thermoelectric and energy materials research. Ag/Sb cationic ordering in polycrystalline AgSbTe2 was a challenging issue for a long time: their ordered arrangement in the cationic sublattice in polycrystalline samples remained elusive despite multiple theoretical predictions and experimental studies. Recently, selective cation doping has been used to enhance the Ag/Sb ordering, and cation ordered nanoscale (2–4 nm) domains were observed in polycrystalline AgSbTe2, which reduce lattice thermal conductivity. The enhanced cation ordering also delocalizes disorder-induced localized electronic states, and consequently the electronic transport enhances. In this Focus Review, we provide the details of the rational design of a high-performance thermoelectric material using the recently developed atomic order–disorder optimization strategy with AgSbTe2 as an example. Atomic disorder is ubiquitous in most thermoelectric materials, and the atomic order–disorder optimization strategy applies to a large variety of thermoelectric materials.},
  author       = {Ghosh, Tanmoy and Roychowdhury, Subhajit and Dutta, Moinak and Biswas, Kanishka},
  issn         = {2380-8195},
  journal      = {ACS Energy Letters},
  keywords     = {Materials Chemistry, Energy Engineering and Power Technology, Fuel Technology, Renewable Energy, Sustainability and the Environment, Chemistry (miscellaneous)},
  number       = {8},
  pages        = {2825--2837},
  publisher    = {American Chemical Society},
  title        = {{High-performance thermoelectric energy conversion: A tale of atomic ordering in AgSbTe2}},
  doi          = {10.1021/acsenergylett.1c01184},
  volume       = {6},
  year         = {2021},
}