Ashvini Vallipuram

Université de Sherbrooke

*This is an algorithmically generated author record based on publicly available information.

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Université de Sherbrooke

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Ashvini Vallipuram has a total of 30 co-authors. Here are the top co-authors by number of shared publications:

Emma Campillo
Université de Sherbrooke
3 shared publications
Gaël Grissonnanche
Laboratoire des Solides Irradiés
3 shared publications
Jordan Baglo
Université de Sherbrooke
3 shared publications
Louis Taillefer
Institut quantique Département de physique & RQMP Université de Sherbrooke J1K 2R1 Sherbrooke Québec Canada
3 shared publications
Manel Mezidi
Université de Sherbrooke
3 shared publications
Lu Chen
Université de Sherbrooke
2 shared publications

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- 14 September 2026
- Published by American Physical Society (APS) in Physical Review B
Electronic mean free path of the cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8 + δ from thermal Hall conductivity
by Emma Campillo, Manel Mezidi, Lu Chen, Ashvini Vallipuram, Jordan Baglo, Munkhtuguldur Altangerel, Gaël Grissonnanche, Genda Gu, Louis Taillefer
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- 14 September 2026
- Published by American Physical Society (APS) in Physical Review B
Electronic mean free path of the cuprate superconductor Bi 2 Sr 2 CaCu 2 O 8 + δ from thermal Hall conductivity
by Emma Campillo, Manel Mezidi, Lu Chen, Ashvini Vallipuram, Jordan Baglo, Munkhtuguldur Altangerel, Gaël Grissonnanche, Genda Gu, Louis Taillefer
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- 16 March 2026
- Published by American Chemical Society (ACS) in Nano Letters
Observation of Microscopic Domain Effects in the Metal–Insulator Transition of Thin-Film NdNiO ₃
by Lucy S. Nathwani, Anne Ruperto, Ashvini Vallipuram, Abigail Y. Jiang, Grace A. Pan, Dan Ferenc Segedin, Ari B. Turkiewicz, Charles M. Brooks, Jarad A. Mason, Qichen Song, et al.
Perovskite oxides display correlated electrical, magnetic, and thermal properties that can be further tuned in the thin-film limit, making them contenders for next-generation electronics. Measuring thermal transport in thin films is challenging, because traditional techniques are dominated by the substrate. Here, frequency-domain thermoreflectance (FDTR) of an epitaxial NdNiO₃ thin film reveals a sharp change in out-of-plane thermal conductivity across the metal–insulator transition. Complementary frequency-domain photoreflectance (FDPR) reveals a large change in ambipolar diffusivity of photoexcited carriers. While the in-plane electrical resistance shows large hysteresis, out-of-plane thermal and charge transport shows negligible hysteresis. We attribute this discrepancy to anisotropy in the percolation of nanoscale domains across the transition as the film thickness approaches the domain length scale. We establish FDTR and FDPR as sensitive probes of quantum material phase transitions and highlight NdNiO₃ for thermal control and memory applications.
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- 16 March 2026
- Published by American Chemical Society (ACS) in Nano Letters
Observation of Microscopic Domain Effects in the Metal–Insulator Transition of Thin-Film NdNiO ₃
by Lucy S. Nathwani, Anne Ruperto, Ashvini Vallipuram, Abigail Y. Jiang, Grace A. Pan, Dan Ferenc Segedin, Ari B. Turkiewicz, Charles M. Brooks, Jarad A. Mason, Qichen Song, et al.
Perovskite oxides display correlated electrical, magnetic, and thermal properties that can be further tuned in the thin-film limit, making them contenders for next-generation electronics. Measuring thermal transport in thin films is challenging, because traditional techniques are dominated by the substrate. Here, frequency-domain thermoreflectance (FDTR) of an epitaxial NdNiO₃ thin film reveals a sharp change in out-of-plane thermal conductivity across the metal–insulator transition. Complementary frequency-domain photoreflectance (FDPR) reveals a large change in ambipolar diffusivity of photoexcited carriers. While the in-plane electrical resistance shows large hysteresis, out-of-plane thermal and charge transport shows negligible hysteresis. We attribute this discrepancy to anisotropy in the percolation of nanoscale domains across the transition as the film thickness approaches the domain length scale. We establish FDTR and FDPR as sensitive probes of quantum material phase transitions and highlight NdNiO₃ for thermal control and memory applications.
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Cited by 3
- 18 June 2025
- Published by American Physical Society (APS) in Physical Review B
Thermal Hall conductivity in the strongest cuprate superconductor : Estimate of the mean free path in the trilayer cuprate HgBa $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{8 + δ}$
by Munkhtuguldur Altangerel, Quentin Barthélemy, Étienne Lefrançois, Jordan Baglo, Manel Mezidi, Gaël Grissonnanche, Ashvini Vallipuram, Emma Campillo, Anne Forget, Dorothée Colson, et al.
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- 18 June 2025
- Published by American Physical Society (APS) in Physical Review B
Thermal Hall conductivity in the strongest cuprate superconductor : Estimate of the mean free path in the trilayer cuprate HgBa $_{2}$ Ca $_{2}$ Cu $_{3}$ O $_{8 + δ}$
by Munkhtuguldur Altangerel, Quentin Barthélemy, Étienne Lefrançois, Jordan Baglo, Manel Mezidi, Gaël Grissonnanche, Ashvini Vallipuram, Emma Campillo, Anne Forget, Dorothée Colson, et al.
Cited by 3
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Cited by 23
- 23 July 2024
- Published by American Physical Society (APS) in Physical Review B
Role of magnetic ions in the thermal Hall effect of the paramagnetic insulator ${TmVO}_{4}$
by Ashvini Vallipuram, Lu Chen, Emma Campillo, Manel Mezidi, Gaël Grissonnanche, Marie-Eve Boulanger, Étienne Lefrançois, Mark P. Zic, Yuntian Li, Ian R. Fisher, et al.
In a growing number of materials, phonons have been found to generate a thermal Hall effect, but the underlying mechanism remains unclear. Inspired by previous studies that revealed the importance of ${Tb}^{3 +}$ ions in generating the thermal Hall effect in a family of pyrochlores, we investigated the role of ${Tm}^{3 +}$ ions in ${TmVO}_{4}$ , a paramagnetic insulator with a different crystal structure. We observe a negative thermal Hall conductivity in ${TmVO}_{4}$ with a magnitude such that the Hall angle, $| κ_{x y} / κ_{x x} |$ , is approximately $1 \times 10^{- 3}$ at $H$ = 15 T and $T$ = 20 K, typical for a phonon-generated thermal Hall effect. In contrast to the negligible $κ_{x y}$ found in the nonmagnetic pyrochlore analog (where the ${Tb}^{3 +}$ ions are replaced with $Y^{3 +}$ ), we observe a negative $κ_{x y}$ in ${YVO}_{4}$ with a Hall angle of magnitude comparable to that of ${TmVO}_{4}$ . This shows that the ${Tm}^{3 +}$ ions are not essential for the thermal Hall effect in this family of materials. Interestingly, at an intermediate Y concentration of $x = 0.3$ in ${Tm}_{1 - x} Y_{x} {VO}_{4}, κ_{x y}$ was found to have a positive sign, pointing to the importance of impurities in the thermal Hall effect of phonons.
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- 23 July 2024
- Published by American Physical Society (APS) in Physical Review B
Role of magnetic ions in the thermal Hall effect of the paramagnetic insulator ${TmVO}_{4}$
by Ashvini Vallipuram, Lu Chen, Emma Campillo, Manel Mezidi, Gaël Grissonnanche, Marie-Eve Boulanger, Étienne Lefrançois, Mark P. Zic, Yuntian Li, Ian R. Fisher, et al.
In a growing number of materials, phonons have been found to generate a thermal Hall effect, but the underlying mechanism remains unclear. Inspired by previous studies that revealed the importance of ${Tb}^{3 +}$ ions in generating the thermal Hall effect in a family of pyrochlores, we investigated the role of ${Tm}^{3 +}$ ions in ${TmVO}_{4}$ , a paramagnetic insulator with a different crystal structure. We observe a negative thermal Hall conductivity in ${TmVO}_{4}$ with a magnitude such that the Hall angle, $| κ_{x y} / κ_{x x} |$ , is approximately $1 \times 10^{- 3}$ at $H$ = 15 T and $T$ = 20 K, typical for a phonon-generated thermal Hall effect. In contrast to the negligible $κ_{x y}$ found in the nonmagnetic pyrochlore analog (where the ${Tb}^{3 +}$ ions are replaced with $Y^{3 +}$ ), we observe a negative $κ_{x y}$ in ${YVO}_{4}$ with a Hall angle of magnitude comparable to that of ${TmVO}_{4}$ . This shows that the ${Tm}^{3 +}$ ions are not essential for the thermal Hall effect in this family of materials. Interestingly, at an intermediate Y concentration of $x = 0.3$ in ${Tm}_{1 - x} Y_{x} {VO}_{4}, κ_{x y}$ was found to have a positive sign, pointing to the importance of impurities in the thermal Hall effect of phonons.
Cited by 23