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Strain as a tool to stabilize the isotropic triangular lattice in a geometrically frustrated organic quantum magnet

T0 review · 3 major / 4 minor · reviewed 2026-08-06 · deepseek-v4-flash

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Pith's one-line read This paper experimentally demonstrates that anisotropic strain continuously tunes the frustration ratio $t'/t$ of the triangular-lattice quantum magnet $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ across the isotropic point, revealing a new phase at…

desk verdict A careful ECE study that maps strain tuning of a frustrated organic magnet, but the strain-to-t'/t calibration is internally inconsistent and needs fixing. read the letter →

arxiv 2506.23813 v2 pith:BHNQXRCM submitted 2025-06-30 cond-mat.str-el

Francisco Lieberich , Yohei Saito , Yassine Agarmani , Takahiko Sasaki , Naoki Yoneyama , Stephen M. Winter , Michael Lang , Elena Gati This is my paper · ORCID
classification cond-mat.str-el
keywords geometricfrustrationtriangularlatticequantumspinliquidelastocaloriceffectuniaxialstrainMottinsulatorκ-(ET)2Cu2(CN)3
verification ladder T0 review T1 audit T2 compute T3 formal

The pith

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The reading

This paper tries to establish that anisotropic mechanical strain is a clean, continuous, disorder-free dial for geometric frustration in the organic quantum magnet $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$, a leading candidate for a quantum spin liquid. Using elastocaloric measurements under uniaxial compression along two crystal axes, the authors map a temperature--strain phase diagram spanning frustration ratios from $t'/t \approx 0.78$ to $1.04$. They find that the spin-gapped ground state below $T^* \approx 6$ K survives all the way to the isotropic triangular lattice ($t'/t = 1$), and that a new, previously unknown phase transition appears when compression along the $c$-axis lowers the frustration below $t'/t \approx 0.8$. If correct, the work gives experimentalists a way to reach the perfectly frustrated lattice in a real material and gives theorists a sharp benchmark for calculations of the triangular-lattice Hubbard model.

What carries the argument

The central tool is the elastocaloric effect, $\eta = (\Delta T/\Delta\varepsilon)_S$, the adiabatic temperature change per unit strain, which is proportional to the strain derivative of the entropy; because $\eta$ vanishes whenever the entropy is extremal, the sign change of the anomaly at $T^*$ locates the strain of maximum entropy, and hence of maximum frustration, directly. The conceptual model is the dimer-Hubbard description of the organic salt, in which each (ET)$_2$ dimer carries a spin-1/2 and the degree of frustration is set by the ratio $t'/t$ of the two nearest-neighbour hopping amplitudes. To convert measured strains into $t'/t$, the paper uses derivatives $\mathrm{d}t/\mathrm{d}\varepsilon$ and $\mathrm{d}t'/\mathrm{d}\varepsilon$ obtained from density-functional calculations of the ambient-pressure crystal structure at different temperatures, combined with an assumed Poisson ratio of 1/3 to account for the strain perpendicular to the pressure axis.

What would settle it

Two checks would settle the central claim: first, measure the specific heat under the same $c$-axis compressions, since the modified Ehrenfest analysis predicts a jump $\Delta C \approx 0.4$ J/(mol K) at $T_+$ that should track the elastocaloric step as strain varies; second, measure the crystal structure in situ under uniaxial strain, which would confirm or correct the entire quantitative $t'/t$ axis, including the identification of the isotropic point at $\varepsilon_0 \approx -0.55\%$, which currently rests on extrapolated density-functional derivatives and an assumed Poisson ratio.

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Extended reading notes

Core claim

The paper's central claim is that compressing $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ along the crystallographic $b$-axis raises the frustration ratio $t'/t$ through and beyond the isotropic point $t'/t = 1$, while compression along the $c$-axis lowers it toward the square-lattice limit. The elastocaloric data show that the spin-gapped phase below $T^*$ remains stable across the entire studied range ($0.78 \lesssim t'/t \lesssim 1.04$), including at maximum frustration, and that the elastocaloric anomaly at $T^*$ changes sign at the strain $\varepsilon_0 \approx -0.55\%$ that the authors identify with the isotropic lattice: at this strain the entropy is maximal and $T^*$ reaches a minimum. Under $c$-axis compression, a second, step-like anomaly appears at $T_+$ once $t'/t \lesssim 0.8$, signalling a new thermodynamic phase that the authors argue is most likely an antiferromagnetically ordered parent state, consistent with numerical predictions for the anisotropic triangular-lattice Hubbard model. Finally, the paper argues that the long-debated '6 K anomaly' at $T^*$ is a first-order transition, because the valence-bond-solid and intra-dimer charge-order parameters that set in together at $T^*$ break different symmetries and must therefore couple strongly attractively.

Load-bearing premise

The load-bearing premise is the conversion from measured strain to frustration ratio: the $t'/t$ values quoted in the phase diagram are extrapolated from density-functional calculations of the uncompressed crystal at different temperatures, joined with an assumed sideways-contraction factor (Poisson ratio) of one third, because no structural measurement of this material under strain exists, and if that mapping is wrong the placement of the isotropic point and the quoted frustration range shift.

Editorial extensions

If this is right

  • The spin-gapped ground state of $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ is stable up to and beyond the isotropic triangular lattice, so the '6 K anomaly' does not signal an instability of the frustrated state at maximum frustration.
  • A distinct phase transition at $T_+$ appears for $t'/t \lesssim 0.8$ under $c$-axis compression, with a step-like anomaly characteristic of a second-order transition and an estimated specific-heat jump consistent with electronic ordering transitions in the $\kappa$-(ET)$_2$X family; the onset value matches numerical predictions for antiferromagnetic order in the triangular-lattice Hubbard model.
  • The 6 K transition is first order across the entire strain range, implying that the '6 K anomaly' marks a coupled valence-bond-solid plus intra-dimer charge-order transition rather than a simple second-order ordering.
  • The experimentally determined phase diagram as a function of frustration provides a reference point for testing how reliably state-of-the-art calculations of the frustrated Hubbard model capture real-material physics near $t'/t \approx 1$.
  • The combination of piezo-driven uniaxial strain and elastocaloric thermometry is transferable to other frustrated systems, such as kagome or delafossite triangular-lattice magnets, where clean frustration tuning has so far been difficult.

Reading between the lines

Editorial extensions of the paper, not claims the author makes directly.

  • If in situ diffraction under strain ever replaces the extrapolated density-functional mapping, the quantitative $t'/t$ axis and the exact strain assigned to the isotropic point could shift; the topological structure of the phase diagram, a stable gapped phase at the isotropic point plus a new phase at low frustration, would likely survive such a rescaling.
  • The sign change of the elastocaloric anomaly under $b$-axis strain could function as a model-independent 'frustration meter': locating the strain of maximal entropy in other triangular-lattice materials would not require any theoretical conversion of strain to hopping parameters.
  • The polycritical point where the $T^*$ and $T_+$ lines meet is an unusually clean experimental realization of competing-order physics, and dielectric or optical measurements under the same strains could decide whether $T_+$ breaks spin symmetry (antiferromagnet) or charge symmetry (charge order), which thermodynamic data alone cannot distinguish.
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Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, and a circularity audit.

Referee Report

3 major / 4 minor

Summary. The manuscript reports elastocaloric effect (ECE) measurements on the frustrated organic Mott insulator κ-(ET)2Cu2(CN)3 under large anisotropic strain applied along the b- and c-axes. The authors validate their ECE data against literature thermal expansion and specific heat data near zero strain, demonstrate reversibility of the strain cycles, and construct a temperature-strain phase diagram. For c-axis compression they find a new transition at T+ that appears for εc ≲ -0.62% and is attributed to a less frustrated parent phase; for b-axis compression the 6 K anomaly weakens and changes sign in the ECE at ε0 ≈ -0.55%, which the authors interpret as the strain at which the lattice becomes the isotropic triangular lattice. Using DFT-derived derivatives from temperature-dependent structural data (Ref. [12]) and an assumed Poisson ratio of 1/3, they convert strain to the frustration ratio t'/t, obtaining a range 0.78 ≲ t'/t ≲ 1.04 and concluding that the spin-gapped phase is stable at maximum frustration. A Landau free-energy model is used to argue that the T* transition is first order and to propose a polycritical point involving valence-bond, charge-order, and antiferromagnetic order parameters.

Significance. If the quantitative calibration were sound, this would be a notable experimental contribution: it introduces ECE as a thermodynamic probe for frustrated magnets, provides the first continuous strain-tuned phase diagram for a triangular-lattice spin-liquid candidate, and identifies a new phase at lower frustration whose onset appears consistent with numerical predictions for the triangular-lattice Hubbard model. The validation of the ECE against ambient-pressure thermodynamic data, the demonstrated reversibility across multiple samples, and the explicit two-order- and three-order-parameter Landau modeling are concrete strengths. However, the paper's signature quantitative claims—that b-axis strain reaches the isotropic point at ε0 ≈ -0.55% and that the spin gap is stable at t'/t ≈ 1—rest entirely on a strain-to-t'/t conversion that, as written, is internally inconsistent and based on an unverified transfer of temperature-driven lattice changes to uniaxial-strain-induced distortions. The qualitative picture of strain tuning frustration is plausible and interesting, but the quantitative axis and the associated benchmark claims are not yet secured.

major comments (3)
  1. [Supplementary Information, Eqs. (4)-(7), (15)-(16) and main text Fig. 3A] The central quantitative mapping from strain to frustration is internally inconsistent. Using the manuscript's own linear relations, t(εb) = 49.4 + 250 εb and t'(εb) = 42.5 - 676 εb (SI Eqs. (15)-(16)), setting t = t' gives εb = -0.745%. The main text, however, identifies ε0 ≈ -0.55% as the strain at which the ECE anomaly changes sign and associates this with t'/t ≈ 1. At εb = -0.55%, the same equations yield t'/t ≈ 0.96, not 1. This is a discrepancy of about 35% of the strain interval from zero strain to the derived isotropic point, and it directly undermines the statements in the main text that 'the t'/t estimates confirm that the spin gap is stable at maximum frustration (t'/t ≈ 1)' and that the new phase appears at t'/t ≲ 0.82. Because the t'/t axis is the only quantitative link between the measured strain and the theoretical model, the identification of ε0 with the isotropic triangular lattice is not supported by the present analysis. The authors should either reconcile the calibration so that the sign-change strain and the derived isotropic point coincide, or present the phase diagram versus strain only and avoid quantitative claims about t'/t.
  2. [Supplementary Information, 'Estimated changes of the triangular-lattice Hubbard model parameters with b- and c-axis…] The conversion from strain to t'/t uses partial derivatives dt/dεb, dt'/dεb, dt/dεc, and dt'/dεc obtained from temperature-driven lattice changes at ambient pressure (Ref. [12]) and an assumed Poisson ratio of 1/3, as the SI itself states that no structural data exist for κ-(ET)2Cu2(CN)3 under uniaxial pressure. The two-regime extraction assumes constant partial derivatives and a clean decoupling of the temperature path into b- and c-axis strain changes. Even if the internal inconsistency in the first comment were fixed, these assumptions are load-bearing for every quantitative t'/t value in Fig. 3A, including the claims that the maximum frustration point is reached and that the spin gap is stable there. The authors should either validate this mapping with direct first-principles calculations of the lattice-strain dependence of t and t', or substantially soften the quantitative conclusions and clearly label the t'/t axis as a schematic estimate rather than a calibrated scale.
  3. [Main text, Fig. 3A and Discussion] The placement of the polycritical point at (εc, T) ≈ (-0.55%, 7.5 K) is not obviously consistent with the described appearance of the T+ phase. In the results, the T+ anomaly is reported for εc ≲ -0.62% (Fig. 2D and accompanying text), while Fig. 3A and the Discussion state εc ≲ -0.55% for the new phase and the polycritical point. The authors should clarify whether the threshold for T+ is -0.55% or -0.62% and ensure that the phase diagram, the phase-boundary extraction, and the text agree.
minor comments (4)
  1. [Supplementary Information, Eq. (14) and surrounding text] The text after Eq. (13) reads 'or a typical material, Poisson's ratio is approximately 1/3'; this should be 'For a typical material'. There is also an empty equation number (14) left in the manuscript, which should be removed.
  2. [Main text, Fig. 2D caption and Fig. 3A caption] The threshold for the appearance of the T+ phase is given as approximately -0.62% in the Fig. 2D caption and as approximately -0.55% in the Fig. 3A caption and in the text. Please harmonize these values or explain the difference.
  3. [Supplementary Information, 'Elastocaloric effect at a first-order phase transition'] The description of the ECE at a broadened first-order transition is clear, but the statement in the main text that the 'symmetric peak in ηi at T* supports the first-order nature of T*' would be more convincing if the predicted symmetric line shape were compared quantitatively with the data, rather than only qualitatively.
  4. [Main text, Materials and Methods] The sentence 'The sample carrier is designed such that only compression can be applied to our sample to determine the zero-strain state with high precision' is a bit misleading because the subsequent paragraphs explain that a small non-zero tuning strain is required to close the gap; please rephrase to state that the zero-force state can be determined precisely, while the ECE measurement uses a small finite strain.

Circularity Check

0 steps flagged · score 2.0 of 10

No significant circularity: the experimental phase diagram is self-contained, and the t'/t axis is an independent DFT-based calibration applied after the measurements; the anchoring of ε0 to t'/t ≈ 1 is internally inconsistent with the SI's own mapping, which is a support/correctness caveat rather than a circular derivation step.

full rationale

The paper's central derivation chain is: direct elastocaloric measurements of κ-(ET)2Cu2(CN)3 under b- and c-axis compression give η_i(T, ε); peak positions define T*(ε) and the new T+(ε) phase; the ηan sign change at ε0 ≈ −0.55% under b-axis strain is an experimental observable linked by Eq. (1) to an entropy extremum. The t'/t axis is overlaid afterwards using DFT-derived linear derivatives dt/dεb = 218 meV, dt'/dεb = −660 meV, dt/dεc = −96 meV, dt'/dεc = 48 meV (SI Eqs. (4)-(7)) taken from Ref. [12], plus a stated Poisson-ratio assumption of 1/3 (SI Eqs. (15)-(18)). None of the phase boundaries or the new-phase discovery is fitted from, or predicted by, the model parameters; the Landau free-energy and Ehrenfest analyses are used to rationalize the measured topology, not to generate it. The t'/t calibration is therefore an applied input, not a fitted parameter renamed as a prediction. The one overlapping-author citation (Ref. [12] includes co-author M. Lang) is prior published DFT work whose stated assumptions do not include the target results (spin-gap stability, T+ onset), so per the reviewing rules it is real evidence rather than load-bearing self-citation. Two caveats are flagged, both as support/correctness risks rather than circularity: (i) the SI explicitly concedes that "no structural data exists for κ-(ET)2Cu2(CN)3 under strain", so the mapping is a temperature-driven proxy extrapolated linearly to ≈ −1% strain with an assumed Poisson ratio; (ii) the identification of ε0 with "t'/t ≈ 1" (Fig. 3 caption and main text) is not exactly reproduced by the SI's own Eqs. (15)-(16), which place t'/t = 1 at εb ≈ −0.745% and give t'/t ≈ 0.96 at ε0 = −0.55%; the claim that T* adopts a minimum and ηan changes sign "when t'/t is ≈ 1" therefore rests partly on the symmetry-based association of ε0 with the isotropic lattice rather than on the DFT mapping. This weakens the quantitative support for "maximum frustration at ε0" but does not make any measured result equivalent to its inputs by construction. Verdict: no significant circularity.

Assumptions & free parameters 3 free parameters · 5 assumptions · 0 invented entities

The central claim rests on a small number of assumptions: standard thermodynamics for the ECE, the effective-dimer model, and an ad hoc mapping from strain to t'/t using temperature-derived DFT derivatives and an assumed Poisson ratio. No new physical entities are introduced; the T+ phase is a proposed order (AFM or CO) within known physics.

free parameters (3)
  • Poisson ratio = 1/3 (assumed)
    Used in the SI to convert uniaxial strain into perpendicular strains when estimating t'(ε); no measured value for this material is available.
  • Strain derivatives dt/dεb, dt'/dεb, dt/dεc, dt'/dεc = 218, -660, -96, 48 meV
    Linear fits to DFT-computed hopping parameters versus temperature-induced lattice strain from Ref [12]; used to map applied strain to t'/t.
  • Landau model parameters (a1,a2,b1,b2,c1,c2,λ1,λ2,λ3) = e.g., a2=5, b2=10, c2=10, λ1=-18, λ3=15 (unitless)
    Chosen in the Supplementary Information to reproduce the observed phase diagram topology; they are not determined from independent measurements.
assumptions (5)
  • standard math Thermodynamic relation η = - (∂S/∂ε)/(∂S/∂T)
    Eq. (1) in the main text; used to interpret ECE signals.
  • domain assumption Effective-dimer triangular-lattice Hubbard model with td >> t, t'
    Assumed for the material; required for the t'/t mapping to be meaningful.
  • ad hoc to paper Temperature-induced lattice changes at ambient pressure can represent uniaxial-pressure-induced strain
    SI section 'Estimated changes...' uses temperature-dependent structure from Ref [12] to derive dt/dε and dt'/dε; validity under applied pressure is not established.
  • standard math Landau theory for coupled order parameters
    Used in the SI to model phase diagram topology and argue for a first-order VBS+CO transition.
  • domain assumption VBS and CO have distinct symmetries and couple attractively
    Based on literature evidence (Refs 14,23,29,33,41); used to argue T* must be first order.

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Cite this review

Pith. "Pith review of Strain as a tool to stabilize the isotropic triangular lattice in a geometrically frustrated organic quantum magnet." pith.science (2026). https://pith.science/paper/BHNQXRCM

@misc{pith2026250623813,
  author       = {Pith},
  title        = {Pith review of: Strain as a tool to stabilize the isotropic triangular lattice in a geometrically frustrated organic quantum magnet},
  year         = {2026},
  howpublished = {\url{https://pith.science/paper/BHNQXRCM}},
  note         = {Machine review of arXiv:2506.23813}
}
abstract

Geometric frustration is a key ingredient in the emergence of exotic states of matter, such as the quantum spin liquid in Mott insulators. While there has been intense interest in experimentally tuning frustration in candidate materials, achieving precise and continuous control has remained a major hurdle -- particularly in accessing the properties of the ideally frustrated lattice. Here, we show that large, finely controlled anisotropic strains can effectively tune the degree of geometric frustration in the Mott insulating $\kappa$-(ET)$_2$Cu$_2$(CN)$_3$ -- a slightly anisotropic triangular-lattice quantum magnet. Using thermodynamic measurements of the elastocaloric effect, we experimentally map out a temperature-strain phase diagram that captures both the ground state of the isotropic lattice and the less frustrated parent state. Our results provide a new benchmark for calculations of the triangular-lattice Hubbard model as a function of frustration and highlight the power of lattice engineering as a route to realizing perfectly frustrated quantum materials.

Figures

Figures reproduced from arXiv: 2506.23813 by the authors.

Figure 1
Figure 1. FIG. 1 [PITH_FULL_IMAGE:figures/full_fig_p003_1.png] view at source ↗
Figure 2
Figure 2. FIG. 2 [PITH_FULL_IMAGE:figures/full_fig_p005_2.png] view at source ↗
Figure 3
Figure 3. FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p006_3.png] view at source ↗

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Forward citations

Cited by 1 Pith paper

Reviewed papers in the Pith corpus that reference this work. Sorted by Pith novelty score. Full citation record

  1. Probing multipolar order in the candidate altermagnet MnF$_2$ through the elastocaloric effect under strain

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    Elastocaloric measurements on MnF2 reveal crossover lines scaling as (strain × magnetic field)^{2/3}, thermodynamic evidence for the predicted d-wave altermagnetic octupolar order.

Reference graph

Works this paper leans on

55 extracted references · 53 canonical work pages · cited by 1 Pith paper

  1. [12]

    H. O. Jeschke, M. de Souza, R. Valent ´ ı, R. S. Manna, M. Lang, and J. A. Schlueter,Temperature dependence of structural and electronic properties of the spin-liquid candidate κ-(BEDT-TTF)2Cu2(CN)3, Phys. Rev. B 85, 035125 (2012)

    work page 2012

  2. [1]

    Balents, Spin liquids in frustrated magnets , Nature 464, 199 (2010)

    L. Balents, Spin liquids in frustrated magnets , Nature 464, 199 (2010)

    work page 2010

  3. [2]

    Y. Zhou, K. Kanoda, and T.-K. Ng, Quantum spin liquid states , Reviews of Modern Physics 89, 025003 (2017)

    work page 2017

  4. [3]

    Broholm, R

    C. Broholm, R. Cava, S. Kivelson, D. Nocera, M. Norman, and T. Senthil, Quantum spin liquids , Science 367, eaay0668 (2020)

    work page 2020

  5. [4]

    Moessner and A

    R. Moessner and A. P. Ramirez, Geometrical frustration, Physics Today 59, 24 (2006)

    work page 2006

  6. [5]

    Kagawa, T

    F. Kagawa, T. Sato, K. Miyagawa, K. Kanoda, Y. Tokura, K. Kobayashi, et al., Charge-cluster glass in an organic conductor, Nature Physics 9, 419 (2013)

    work page 2013

  7. [6]

    Sasaki, K

    S. Sasaki, K. Hashimoto, R. Kobayashi, K. Itoh, S. Iguchi, Y. Nishio, et al., Crystallization and vitrification of electrons in a glass-forming charge liquid , Science 357, 1381 (2017)

    work page 2017

  8. [7]

    L. Ye, S. Fang, M. Kang, J. Kaufmann, Y. Lee, C. John, et al.,Hopping frustration-induced flat band and strange metallicity in a kagome metal , Nature Physics 20, 610 (2024)

    work page 2024

Show all 55 references
  1. [8]

    S. D. Wilson and B. R. Ortiz, A V3Sb5 kagome superconductors, Nature Reviews Materials 9, 420 (2024)

    2024

  2. [9]

    Lacroix, P

    C. Lacroix, P. Mendels, and F. Mila, Introduction to Frustrated Magnetism: Materials, Experiments, Theory , Springer Series in Solid-State Sciences (Springer Berlin Heidelberg, 2011)

    2011

  3. [10]

    Senthil, A

    T. Senthil, A. Vishwanath, L. Balents, S. Sachdev, and M. P. A. Fisher, Deconfined Quantum Critical Points, Science 303, 1490 (2004)

    2004

  4. [11]

    H. C. Kandpal, I. Opahle, Y.-Z. Zhang, H. O. Jeschke, and R. Valent ´ ı, Revision of model parameters for κ-type charge transfer salts: An ab initio study , Phys. Rev. Lett. 103, 067004 (2009)

    2009

  5. [13]

    Miksch, A

    B. Miksch, A. Pustogow, M. J. Rahim, A. A. Bardin, K. Kanoda, J. A. Schlueter, et al., Gapped magnetic ground state in quantum spin liquid candidate κ-(BEDT-TTF)2Cu2(CN)3, Science 372, 276 (2021)

    2021

  6. [14]

    R. S. Manna, M. de Souza, A. Br¨ uhl, J. A. Schlueter, and M. Lang, Lattice Effects and Entropy Release at the Low- Temperature Phase Transition in the Spin-Liquid Candidate κ−(BEDT−TTF)2Cu2(CN)3, Phys. Rev. Lett. 104, 016403 (2010)

    2010

  7. [15]

    R. S. Manna, S. Hartmann, E. Gati, J. A. Schlueter, M. De Souza, and M. Lang, Low-Temperature Lattice Effects in the Spin-Liquid Candidate κ-(BEDT-TTF)2Cu2(CN)3, Crystals 8 (2018)

    2018

  8. [16]

    M. E. Barber, A. Steppke, A. P. Mackenzie, and C. W. Hicks, Piezoelectric-based uniaxial pressure cell with integrated force and displacement sensors , Review of Scientific Instruments 90, 023904 (2019)

    2019

  9. [17]

    M. S. Ikeda, J. A. W. Straquadine, A. T. Hristov, T. Worasaran, J. C. Palmstrom, M. Sorensen, et al., AC elastocaloric effect as a probe for thermodynamic signatures of continuous phase transitions , Review of Scientific Instruments 90, 083902 (2019)

    2019

  10. [18]

    Y.-S. Li, M. Garst, J. Schmalian, S. Ghosh, N. Kikugawa, D. A. Sokolov, et al., Elastocaloric determination of the phase diagram of Sr 2RuO4, Nature 607, 276 (2022)

    2022

  11. [19]

    B. J. Powell and R. H. McKenzie, Quantum frustration in organic Mott insulators: from spin liquids to unconventional superconductors, Reports on Progress in Physics 74, 056501 (2011). 11

    2011

  12. [20]

    Riedl, E

    K. Riedl, E. Gati, and R. Valent ´ ı,Ingredients for generalized models of κ-phase organic charge-transfer salts: A review , Crystals 12 (2022)

    2022

  13. [21]

    Menke, M

    H. Menke, M. Klett, K. Kanoda, A. Georges, M. Ferrero, and T. Sch¨ afer, Superconductivity and Mott Physics in Organic Charge Transfer Materials, Phys. Rev. Lett. 133, 136501 (2024)

    2024

  14. [22]

    Shimizu, K

    Y. Shimizu, K. Miyagawa, K. Kanoda, M. Maesato, and G. Saito, Spin Liquid State in an Organic Mott Insulator with a Triangular Lattice, Phys. Rev. Lett. 91, 107001 (2003)

    2003

  15. [23]

    Abdel-Jawad, I

    M. Abdel-Jawad, I. Terasaki, T. Sasaki, N. Yoneyama, N. Kobayashi, Y. Uesu, et al., Anomalous dielectric response in the dimer Mott insulator κ−(BEDT-TTF)2Cu2(CN)3, Phys. Rev. B 82, 125119 (2010)

    2010

  16. [24]

    Poirier, M

    M. Poirier, M. de Lafontaine, K. Miyagawa, K. Kanoda, and Y. Shimizu, Ultrasonic investigation of the transition at 6 K in the spin-liquid candidate κ-(BEDT-TTF)2Cu2(CN)3, Phys. Rev. B 89, 045138 (2014)

    2014

  17. [25]

    Yamashita, Y

    S. Yamashita, Y. Nakazawa, M. Oguni, Y. Oshima, H. Nojiri, Y. Shimizu, et al., Thermodynamic properties of a spin-1/2 spin-liquid state in a κ-type organic salt , Nature Physics 4, 459 (2008)

    2008

  18. [26]

    Yamashita, N

    M. Yamashita, N. Nakata, Y. Kasahara, T. Sasaki, N. Yoneyama, N. Kobayashi, et al., Thermal-transport measurements in a quantum spin-liquid state of the frustrated triangular magnet κ-(BEDT-TTF)2Cu2(CN)3, Nature Physics 5, 44 (2009)

    2009

  19. [27]

    Isono, T

    T. Isono, T. Terashima, K. Miyagawa, K. Kanoda, and S. Uji, Quantum criticality in an organic spin-liquid insulator κ-(BEDT-TTF)2Cu2(CN)3, Nature Communications 7, 13494 (2016)

    2016

  20. [28]

    Riedl, R

    K. Riedl, R. Valent ´ ı, and S. M. Winter, Critical spin liquid versus valence-bond glass in a triangular-lattice organic antiferromagnet, Nature Communications 10, 2561 (2019)

    2019

  21. [29]

    Matsuura, T

    M. Matsuura, T. Sasaki, M. Naka, J. M¨ uller, O. Stockert, A. Piovano, et al.,Phonon renormalization effects accompanying the 6 K anomaly in the quantum spin liquid candidate κ−(BEDT-TTF)2Cu2(CN)3, Phys. Rev. Res. 4, L042047 (2022)

    2022

  22. [30]

    Pustogow, Y

    A. Pustogow, Y. Kawasugi, H. Sakurakoji, and N. Tajima, Chasing the spin gap through the phase diagram of a frustrated Mott insulator , Nature Communications 14, 1960 (2023)

    2023

  23. [31]

    Shimizu, M

    Y. Shimizu, M. Maesato, and G. Saito, Uniaxial strain effects on Mott and superconducting transitions in κ- (ET)2Cu2(CN)3, Journal of the Physical Society of Japan 80, 074702 (2011)

    2011

  24. [32]

    E. Gati, B. Schmidt, S. L. Bud’ko, A. P. Mackenzie, and P. C. Canfield, Controlling crystal-electric field levels through symmetry-breaking uniaxial pressure in a cubic super heavy fermion , npj Quantum Materials 8, 69 (2023)

    2023

  25. [33]

    Kobayashi, Q.-P

    T. Kobayashi, Q.-P. Ding, H. Taniguchi, K. Satoh, A. Kawamoto, and Y. Furukawa, Charge disproportionation in the spin-liquid candidate κ − (ET)2Cu2(CN)3 at 6 K revealed by 63Cu NQR measurements, Phys. Rev. Res. 2, 042023 (2020)

    2020

  26. [34]

    Jerzembeck, Y.-S

    F. Jerzembeck, Y.-S. Li, G. Palle, Z. Hu, M. Biderang, N. Kikugawa, et al., Tc and the elastocaloric effect of Sr2RuO4 under ⟨110⟩ uniaxial stress: No indications of transition splitting , Phys. Rev. B 110, 064514 (2024)

    2024

  27. [35]

    Riedl, E

    K. Riedl, E. Gati, D. Zielke, S. Hartmann, O. M. Vyaselev, N. D. Kushch, et al., Spin Vortex Crystal Order in Organic Triangular Lattice Compound, Phys. Rev. Lett. 127, 147204 (2021)

    2021

  28. [36]

    M. S. Ikeda, T. Worasaran, E. W. Rosenberg, J. C. Palmstrom, S. A. Kivelson, and I. R. Fisher, Elastocaloric signature of nematic fluctuations , Proceedings of the National Academy of Sciences 118, e2105911118 (2021)

    2021

  29. [37]

    Lunkenheimer, J

    P. Lunkenheimer, J. M¨ uller, S. Krohns, F. Schrettle, A. Loidl, B. Hartmann, et al., Multiferroicity in an organic charge- transfer salt that is suggestive of electric-dipole-driven magnetism , Nature Materials 11, 755 (2012)

    2012

  30. [38]

    E. Gati, J. K. H. Fischer, P. Lunkenheimer, D. Zielke, S. K¨ ohler, F. Kolb, et al., Evidence for electronically driven ferroelectricity in a strongly correlated dimerized bedt-ttf molecular conductor , Phys. Rev. Lett. 120, 247601 (2018). 12

    2018

  31. [39]

    Hassan, S

    N. Hassan, S. Cunningham, M. Mourigal, E. I. Zhilyaeva, S. A. Torunova, R. N. Lyubovskaya, et al., Evidence for a quantum dipole liquid state in an organic quasi–two-dimensional material , Science 360, 1101 (2018)

    2018

  32. [40]

    M. Lang, P. Lunkenheimer, O. Ganter, S. Winter, and J. M¨ uller, Ferroelectric and multiferroic properties of quasi-2d organic charge-transfer salts: A review , Journal of Electronic Materials (2025)

    2025

  33. [41]

    Liebman, K

    J. Liebman, K. Miyagawa, K. Kanoda, and N. Drichko, Novel dipole-lattice coupling in the quantum spin liquid material κ−(BEDT−TTF)2Cu2(CN)3, Phys. Rev. B 110, 165105 (2024)

    2024

  34. [42]

    Szasz and J

    A. Szasz and J. Motruk, Phase diagram of the anisotropic triangular lattice Hubbard model , Phys. Rev. B 103, 235132 (2021)

    2021

  35. [43]

    Yamashita and Y

    S. Yamashita and Y. Nakazawa, Heat capacities of antiferromagnetic dimer-Mott insulators in organic charge-transfer complexes, Journal of Thermal Analysis and Calorimetry 99, 153 (2010)

    2010

  36. [44]

    Szasz, J

    A. Szasz, J. Motruk, M. P. Zaletel, and J. E. Moore, Chiral Spin Liquid Phase of the Triangular Lattice Hubbard Model: A Density Matrix Renormalization Group Study , Phys. Rev. X 10, 021042 (2020)

    2020

  37. [45]

    Wietek, R

    A. Wietek, R. Rossi, F. ˇSimkovic, M. Klett, P. Hansmann, M. Ferrero, et al.,Mott Insulating States with Competing Orders in the Triangular Lattice Hubbard Model , Phys. Rev. X 11, 041013 (2021)

    2021

  38. [46]

    Wietek and A

    A. Wietek and A. M. L¨ auchli, Chiral spin liquid and quantum criticality in extended s = 1 2 heisenberg models on the triangular lattice, Phys. Rev. B 95, 035141 (2017)

    2017

  39. [47]

    Wietek, S

    A. Wietek, S. Capponi, and A. M. L¨ auchli,Quantum electrodynamics in 2 + 1 dimensions as the organizing principle of a triangular lattice antiferromagnet , Phys. Rev. X 14, 021010 (2024)

    2024

  40. [48]

    A. O. Scheie, E. A. Ghioldi, J. Xing, J. A. M. Paddison, N. E. Sherman, M. Dupont, et al., Proximate spin liquid and fractionalization in the triangular antiferromagnet kybse2 , Nature Physics 20, 74 (2024)

    2024

  41. [49]

    Geiser, H

    U. Geiser, H. H. Wang, K. D. Carlson, J. M. Williams, H. A. J. Charlier, J. E. Heindl, et al., Superconductivity at 2.8 K and 1.5 kbar in κ-(BEDT-TTF)2Cu2(CN)3: the first organic superconductor containing a polymeric copper cyanide anion , Inorganic Chemistry 30, 2586 (1991)

    1991

  42. [50]

    C. W. Hicks, M. E. Barber, S. D. Edkins, D. O. Brodsky, and A. P. Mackenzie, Piezoelectric-based apparatus for strain tuning, Review of Scientific Instruments 85, 065003 (2014)

    2014

  43. [51]

    Jerzembeck, H

    F. Jerzembeck, H. S. Røising, A. Steppke, H. Rosner, D. A. Sokolov, N. Kikugawa, et al., The superconductivity of Sr2RuO4 under c-axis uniaxial stress , Nature Communications 13, 4596 (2022)

    2022

  44. [52]

    Rahal, D

    M. Rahal, D. Chasseau, J. Gaultier, L. Ducasse, M. Kurmoo, and P. Day, Isothermal Compressibility and Pressure De- pendence of the Crystal Structures of the Superconducting Charge-Transfer Salt κ-(BEDT-TTF)2Cu(NCS)2 [BEDT-TTF = Bis(ethylenedithio)tetrathiafulvalene], Acta Crys...

    1997

  45. [53]

    E. Rose, C. Loose, J. Kortus, A. Pashkin, C. A. Kuntscher, S. G. Ebbinghaus, et al., Pressure-dependent structural and electronic properties of quasi-one-dimensional (TMTTF) 2PF6, Journal of Physics: Condensed Matter 25, 014006 (2012)

    2012

  46. [54]

    H. M. L. Noad, K. Ishida, Y.-S. Li, E. Gati, V. Stangier, N. Kikugawa, et al., Giant lattice softening at a Lifshitz transition in Sr 2RuO4, Science 382, 447 (2023)

    2023

  47. [55]

    Pustogow, M

    A. Pustogow, M. Bories, A. L¨ ohle, R. R¨ osslhuber, E. Zhukova, B. Gorshunov, et al., Quantum spin liquids unveil the genuine Mott state , Nature Materials 17, 773 (2018). 13 Supplementary T ext Details of Experimental Methods Sample preparation - Experiments were conducted o...

    2018

Pith tools

Reviewed August 6, 2026 · model on record in the stance chip above.