Publications (27)
Nanoscale electromechanical resonators as probes of the charge density wave transition in NbSe
Shamashis Sengupta, Hari S. Solanki, Vibhor Singh +2
We study nanoelectromechanical resonators fabricated from suspended flakes of NbSe (thickness30-50 nm) to probe charge density wave (CDW) physics at nanoscale. Variation…
Tuning mechanical modes and influence of charge screening in nanowire resonators
Hari S. Solanki, Shamashis Sengupta, Sajal Dhara +6
We probe electro-mechanical properties of InAs nanowire (diameter ~ 100 nm) resonators where the suspended nanowire (NW) is also the active channel of a field effect transistor (FE…
Higher-Order Topology in Bismuth
Frank Schindler, Zhijun Wang, Maia G. Vergniory +12
The mathematical field of topology has become a framework to describe the low-energy electronic structure of crystalline solids. A typical feature of a bulk insulating three-dimens…
Size Dependence in Flux-Flow Hall Effect using Time-Dependent Ginzburg-Landau Equations
Vineet Punyamoorty, Aditya Malusare, Shamashis Sengupta +2
We study the Hall effect in square, planar type-II superconductors using numerical simulations of time dependent Ginzburg-Landau (TDGL) equations. The Hall field in some type-II su…
High Q electromechanics with InAs nanowire quantum dots
Hari S. Solanki, Shamashis Sengupta, Sudipta Dubey +7
In this report, we study electromechanical properties of a suspended InAs nanowire (NW) resonator. At low temperatures, the NW acts as the island of a single electron transistor (S…
Facile fabrication of lateral nanowire wrap-gate devices with improved performance
Sajal Dhara, Shamashis Sengupta, Hari S. Solanki +5
We present a simple fabrication technique for lateral nanowire wrap-gate devices with high capacitive coupling and field-effect mobility. Our process uses e-beam lithography with a…
The electric-field-driven intermediate state of three-dimensional superconductors
Ion Cojocari, Enzo Andreani, Paola Verniere +5
The coexistence of superconductivity and finite electric fields may enable access to intriguing forms of electronic states. We demonstrate the emergence of an intermediate state in…
Born-limit scattering and pair-breaking crossover in d-wave superconductivity of (TMTSF)2ClO4
Shota Yano, Kazumi Fukushima, Katsuki Kinjo +8
In the quasi-one-dimensional organic unconventional superconductor (TMTSF)2ClO4, the randomness of the non-centrosymmetric ClO4 anions can be experimentally controlled by adjusting…
Gate-tunable superconductivity at SrTiO3 surface realized by Al layer evaporation
Shamashis Sengupta, Emilie Tisserond, Florence Linez +8
Electronic properties of low dimensional superconductors are determined by many-body-effects. This physics has been studied traditionally with superconducting thin films, and in re…
Emergence of a Non-van der Waals Magnetic Phase in a van der Waals Ferromagnet
Bikash Das, Subrata Ghosh, Shamashis Sengupta +12
Manipulation of long-range order in two-dimensional (2D) van der Waals (vdW) magnetic materials (e.g., CrI, CrSiTe etc.), exfoliated in few-atomic layer, can be achieved vi…
Wide bandwidth nanowire electromechanics on insulating substrates at room temperature
T. S. Abhilash, John P Mathew, Shamashis Sengupta +3
We study InAs nanowire resonators fabricated on sapphire substrate with a local gate configuration. The key advantage of using an insulating sapphire substrate is that it results i…
Plasmon mode modifies the elastic response of a nanoscale charge density wave system
Shamashis Sengupta, Niveditha Samudrala, Vibhor Singh +4
The elastic response of suspended NbSe3 nanowires is studied across the charge density wave phase transition. The nanoscale dimensions of the resonator lead to a large resonant fre…
Universal Fabrication of Two-Dimensional Electron Systems in Functional Oxides
Tobias Chris Rödel, Franck Fortuna, Shamashis Sengupta +9
Two-dimensional electron systems (2DESs) in functional oxides are promising for applications, but their fabrication and use, essentially limited to SrTiO-based heterostructures…
Superconducting nanowires by electron-beam-induced deposition
Shamashis Sengupta, Chuan Li, Cedric Baumier +4
Superconducting nanowires can be fabricated by decomposition of an organometallic gas using a focused beam of Ga ions. However, physical damage and unintentional doping often resul…
Probing thermal expansion of graphene and modal dispersion at low-temperature using graphene NEMS resonators
Vibhor Singh, Shamashis Sengupta, Hari S. Solanki +5
We use suspended graphene electromechanical resonators to study the variation of resonant frequency as a function of temperature. Measuring the change in frequency resulting from a…
Observation of Intrinsic Anderson Localization in Few-Layer ReS
Shreya Paul, Pritam Das, Devarshi Chakrabarty +2
Electron localization phenomena are expected to play an important role in the transport properties of two-dimensional materials. Rhenium disulfide (ReS), with its narrow conduc…
Percolative Instabilities and Sparse-Limit Fractality in 1T-TaS
Poulomi Maji, Md Aquib Molla, Koushik Dey +13
The low-temperature metallic phase of 1T-TaS2 may originate from current- and voltage-driven destabilization of the commensurate charge density wave (CDW) in a strongly correlated…
Transverse resistance due to electronic inhomogeneities in superconductors
Shamashis Sengupta, Alireza Farhadizadeh, Joe Youssef +8
Phase transitions in many-body systems are often associated with the emergence of spatial inhomogeneities. Such features may develop at microscopic lengthscales and are not necessa…
Pressure Induced Anomalous Metal in the Vicinity of the Superconductor Insulator Transition
Roy G. Cohen Song, Mark Nikolaevsky, Amitay Cohen +4
The Superconductor-to-Insulator Transition (SIT) in two-dimensional superconductors occurs due to a competition between superconductivity, quantum interferences, Coulomb interactio…
Magnetic field resistant quantum interferences in bismuth nanowires based Josephson junctions
Chuan Li, A. Kasumov, A. Murani +11
We investigate proximity induced superconductivity in micrometer-long bismuth nanowires con- nected to superconducting electrodes with a high critical field. At low temperature we…
Coupling between quantum Hall state and electromechanics in suspended graphene resonator
Vibhor Singh, Bushra Irfan, Ganesh Subramanian +6
Using graphene resonator, we perform electromechanical measurements in quantum Hall regime to probe the coupling between a quantum Hall (QH) system and its mechanical motion. Mecha…
Field-effect modulation of conductance in VO2 nanobeam transistors with HfO2 as the gate dielectric
Shamashis Sengupta, Kevin Wang, Kai Liu +4
We study field-effect transistors realized from VO2 nanobeams with HfO2 as the gate dielectric. When heated up from low to high temperatures, VO2 undergoes an insulator-to-metal tr…
Density-tuned isotherms and dynamic change at phase transition in a gate-controlled superconducting system
Shamashis Sengupta, Miguel Monteverde, Anil Murani +3
Two-dimensional electron gases in SrTiO3-based heterostructures provide a platform to study the real-time evolution of the macroscopic state with a variation of the carrier density…
Conductance switching and nonequilibrium phase coexistence in superconductors with intermediate bias
Shamashis Sengupta
Superconducting systems may display different types of nonequilibrium states depending on the specific constraints imposed for measurement. We probe current-voltage relations of th…
Tunable thermal conductivity in defect engineered nanowires at low temperatures
Sajal Dhara, Hari S. Solanki, Arvind Pawan R. +7
We measure the thermal conductivity () of individual InAs nanowires (NWs), and find that it is 3 orders of magnitude smaller than the bulk value in the temperature range of 10…
Ballistic edge states in Bismuth nanowires revealed by SQUID interferometry
Anil Murani, Alik Kasumov, Shamashis Sengupta +9
Spin-orbit interactions are known to have drastic effects on the band structure of heavy-element-based materials. Celebrated examples are the recently identified 3D and 2D topologi…
Spontaneous voltage peaks in superconducting Nb channels without engineered asymmetry
Shamashis Sengupta, Miguel Monteverde, Sara Loucif +3
Rectification effects in solid-state devices are a consequence of nonreciprocal transport properties. This phenomenon is usually observed in systems with broken inversion symmetry.…