923 citations · 1.7k across the 55 of their papers we have counts for
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Surpassing Gaussian optimality in multiparameter estimation with indefinite causal order
Sudipta Das, Rivu Gupta, Aditi Sen De +1
We identify single-mode Gaussian probes, generated by displacement and squeezing operations on the vacuum state, which are optimal for the simultaneous estimation of displacement a…
Efficient Pauli-decomposition and multistage state-refinement for tensor network based differential equation solver
Vishwabhushan Suresh Gholap, Himadri Shekhar Dhar, Siddhartha Santra
Classical numerical techniques for solving partial differential equations (PDEs) become computationally expensive as the dimension of the discretized differential operator increase…
Quantum information spreading in inhomogeneous spin ensembles
Rahul Gupta, Florian Mintert, Himadri Shekhar Dhar
We present a Krylov space based theoretical framework for modeling inhomogeneous spin ensembles with arbitrary distributions of spin frequencies and couplings. The framework is the…
Optimally Controlled Storage of a Qubit in an Inhomogeneous Spin Ensemble
Rahul Gupta, Florian Mintert, Himadri Shekhar Dhar
The storage of quantum information in spin-ensembles is limited by practically unavoidable inhomogeneous broadening, and the macroscopic number of spins in such an ensemble makes t…
Cavity-Driven Multispectral Gain for High-Sensitivity NV Center Magnetometers
Himanshu Kumar, Rahul Gupta, Saikat Ghosh +2
We report a cavity-enabled solid-state magnetometer based on an NV ensemble coupled with a dielectric cavity, achieving 12 pT/ sensitivity and a nearly threefold ga…
Quadratic power enhancement in extended Dicke quantum battery
Harsh Sharma, Himadri Shekhar Dhar
We demonstrate a quadratic enhancement of power in a battery consisting of two-level systems or spins interacting with two photonic cavity modes, where one of the modes is in t…
Thermodynamic Probes of Multipartite Entanglement in Strongly Interacting Quantum Systems
Harsh Sharma, Sampriti Saha, A. S. Majumdar +2
Quantifying multipartite entanglement in quantum many-body systems and hybrid quantum computing architectures is a fundamental yet challenging task. In recent years, thermodynamic…
Macroscopic entanglement between localized domain walls inside a cavity
Rahul Gupta, H. Y. Yuan, Himadri Shekhar Dhar
We present a scheme for generating stable and tunable entanglement between two localized Bloch domain walls in nanomagnetic strips kept inside a chiral optical cavity. The entangle…
Cavity Optomechanical Quantum Memory for Twisted Photons Using a Ring BEC
Nilamoni Daloi, Rahul Gupta, Aritra Ghosh +3
We theoretically propose a photonic orbital angular momentum (OAM) quantum memory platform based on an atomic Bose-Einstein condensate confined in a ring trap and placed inside a F…
Sequential information theoretic protocols in continuous variable systems
Sudipta Das, Ayan Patra, Rivu Gupta +2
In order to enable the sequential implementation of quantum information theoretic protocols in the continuous variable framework, we propose two schemes for resource reusability, r…
Quantum error correction for an unresolvable spin ensemble
Harsh Sharma, Himadri Shekhar Dhar, Hoi-Kwan Lau
Spin ensembles are promising quantum technological platforms, but their utility relies on the ability to perform quantum error correction (QEC) for the specific decoherence in thes…
Sensing atomic superfluid rotation beyond the standard quantum limit
Rahul Gupta, Pardeep Kumar, Rina Kanamoto +2
Atomic superfluids formed using Bose-Einstein condensates (BECs) in a ring trap are currently being investigated in the context of superfluid hydrodynamics, quantum sensing and mat…
Nonclassical resource for continuous variable telecloning with non-Gaussian advantage
Sudipta Das, Rivu Gupta, Himadri Shekhar Dhar +1
The telecloning protocol distributes quantum states from a single sender to multiple receivers via a shared entangled state by exploiting the notions of teleportation and approxima…
Photon-photon correlation of condensed light in a microcavity
Yijun Tang, Himadri Shekhar Dhar, Rupert F. Oulton +2
The study of temporal coherence in a Bose-Einstein condensate of photons can be challenging, especially in the presence of correlations between the photonic modes. In this work, we…
Breakdown of Temporal Coherence in Photon Condensates
Yijun Tang, Himadri Shekhar Dhar, Rupert F. Oulton +2
The temporal coherence of an ideal Bose gas increases as the system approaches the Bose-Einstein condensation threshold from below, with coherence time diverging at the critical po…
Observation of collapse and revival in a superconducting atomic frequency comb
E. S. Redchenko, M. Zens, M. Zemlicka +6
Recent advancements in superconducting circuits have enabled the experimental study of collective behavior of precisely controlled intermediate-scale ensembles of qubits. In this w…
Protecting information in a parametrically driven hybrid quantum system
Siddharth Tiwary, Harsh Sharma, Himadri Shekhar Dhar
The transfer and storage of quantum information in a hybrid quantum system, consisting of an ensemble of atoms or spins interacting with a cavity, is adversely affected by the inho…
Periodic cavity state revivals from atomic frequency combs
Matthias Zens, Dmitry O. Krimer, Himadri S. Dhar +1
Spin ensembles with a comb-shaped spectrum have shown exciting properties as efficient quantum memories. Here, we present a rigorous theoretical study of such atomic frequency comb…
Quest for Vortices in Photon Condensates
Himadri S. Dhar, Zai Zuo, João D. Rodrigues +2
We predict that a photon condensate inside a dye-filled microcavity forms long-lived spatial structures that resemble vortices when incoherently excited by a focused pump orbiting…
Transport and localization of light inside a dye-filled microcavity
Himadri S. Dhar, João D. Rodrigues, Benjamin T. Walker +3
The driven-dissipative nature of light-matter interaction inside a multimode, dye-filled microcavity makes it an ideal system to study nonequilibrium phenomena, such as transport.…
Non-critical slowing down of photonic condensation
Benjamin T. Walker, Henry J. Hesten, Himadri S. Dhar +2
We investigate the response of a photonic gas interacting with a reservoir of pumped dye-molecules to quenches in the pump power. In addition to the expected dramatic critical slow…
Effect of long-range interactions on multipartite entanglement in Heisenberg chains
Sudipto Singha Roy, Himadri Shekhar Dhar
It is well known that the notions of spatial locality are often lost in quantum systems with long-range interactions, as exhibited by the emergence of phases with exotic long-range…
Tensor-network approach to compute genuine multisite entanglement in infinite quantum spin chains
Sudipto Singha Roy, Himadri Shekhar Dhar, Aditi Sen De +1
We devise a method based on the tensor-network formalism to calculate genuine multisite entanglement in ground states of infinite spin chains containing spin-1/2 or spin-1 quantum…
Variational Renormalization Group for Dissipative Spin-Cavity Systems: Periodic Pulses of Nonclassical Photons from Mesoscopic Spin Ensembles
Himadri Shekhar Dhar, Matthias Zens, Dmitry O. Krimer +1
Mesoscopic spin ensembles coupled to a cavity offer the exciting prospect of observing complex nonclassical phenomena that pool the microscopic features from a few spins with those…