Kanu Sinha

Interests

Teaching

Undergraduate: Introduction to Quantum Mechanics; Introduction to Quantum Optics and Quantum InformationGraduate: Quantum Optics; Open Quantum Systems

Research

Quantum Optics and Open Quantum Systems: focusing on quantum fluctuation phenomena, collective atom-field Interactions and non-Markovian open quantum sytems. Our research aims to find novel ways to engineer interactions between atoms/atom-like emitters and photons, with the goal to building efficient light-matter interfaces and exploring quantum phenomena at macroscopic scales. We are a theory group working closely with experiments, with the aim to develop novel quantum optics applications in quantum information processing, quantum sensing and metrology, and photonic devices.

Courses

Scholarly Contributions

Journals/Publications

• Alvarez-Giron, W. .., Solano, P., Sinha, K., & Barberis-Blostein, P. .. (2024). Delay-induced spontaneous dark-state generation from two distant excited atoms. Phys. Rev. Res., 6, 023213.
• Izadyari, M., Pusuluk, O., Sinha, K., & Müstecaplıoğlu, Ö. E. (2024). Steady-State Entanglement Generation via Casimir-Polder Interactions.
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  We investigate the generation of steady-state entanglement between two atomsresulting from the fluctuation-mediated Casimir-Polder (CP) interactions near asurface. Starting with an initially separable state of the atoms, we analyzethe atom-atom entanglement dynamics for atoms placed at distances in the rangeof $\sim25$ nm away from a planar medium, examining the effect of mediumproperties and geometrical configuration of the atomic dipoles. We show thatperfectly conducting and superconducting surfaces yield an optimal steady-stateconcurrence value of approximately 0.5. Furthermore, although the generatedentanglement decreases with medium losses for a metal surface, we identify anoptimal distance from the metal surface that assists in entanglement generationby the surface. While fluctuation-mediated interactions are typicallyconsidered detrimental to the coherence of quantum systems at nanoscales, ourresults demonstrate a mechanism for leveraging such interactions forentanglement generation.[Journal_ref: ]
• Jakubec, C., Jarzynski, C., & Sinha, K. (2024). Decoherence and Brownian motion of a polarizable particle near a surface.
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  We analyze the classical and quantized center-of-mass motion of a polarizableparticle interacting with the fluctuations of the electromagnetic (EM) field inthe presence of a medium. As a polarizable particle is immersed in a thermalenvironment, the momentum impulses imparted by the field fluctuations lead tomomentum diffusion and drag for the particle's classical center of mass. Whenconsidering the quantized center-of-mass motion of the particle, these veryfluctuations gain information about its position, leading to decoherence in theposition basis. We derive a position localization master equation for theparticle's quantized center of mass, and examine its classical center-of-massmomentum diffusion, elucidating correspondences between classical and quantumBrownian motion of polarizable particles near media.[Journal_ref: ]
• Jakubec, C., Solano, P., 'cfi}, U., & Sinha, K. (2024). Fluctuation-induced forces on nanospheres in external fields. Phys. Rev. A, 109, 052807.
• Prabhu, A., Parra-Contreras, J., Goldschmidt, E. A., & Sinha, K. (2024). Quantum Electrodynamics with Time-varying Dielectrics.
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  We present a framework for quantization of electromagnetic field in thepresence of dielectric media with time-varying optical properties. Consideringa microscopic model for the dielectric as a collection of matter fieldsinteracting with the electromagnetic environment, we allow for the possibilityof dynamically varying light-matter coupling. We obtain the normal modes of thecoupled light-matter degrees of freedom, showing that the correspondingcreation and annihilation operators obey equal-time canonical commutationrelations. We show that these normal modes can consequently couple to quantumemitters in the vicinity of dynamic dielectric media, and the resultingradiative properties of atoms are thus obtained. Our results are pertinent totime-varying boundary conditions realizable across a wide range ofstate-of-the-art physical platforms and timescales.[Journal_ref: ]
• Sinha, K., & Milonni, P. W. (2024). Scalar QED Model for Polarizable Particles in Thermal Equilibrium or in Hyperbolic Motion in Vacuum. Physics, 6(1), 356--367.
• Sinha, K., Parra-Contreras, J., Das, A., & Solano, P. (2024). Spontaneous Emission in the presence of Quantum Mirrors.
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  Arrays of atoms coupled to waveguides can behave as mirrors. We consider anarray of $\Lambda$-type three-level atoms wherein preparing the atoms in oneground state or another leads to reflection or transmission of the guidedelectromagnetic field; a superposition of the two ground states thuscorresponds to a coherent superposition of mirror-like and transparent boundaryconditions. We analyze the spontaneous emission of an excited two-level atom inthe presence of such a quantum mirror, and inside a cavity formed by quantummirrors, demonstrating that the resulting dynamics of the excited atom canexhibit exotic features, e.g., a superposition of Rabi cycle and exponentialdecay. Our results pave the way for exploring quantum electrodynamics (QED)phenomena in a paradigm wherein boundary conditions can exhibit quantumsuperpositions and correlations.[Journal_ref: ]
• Sone, A., Sinha, K., & Deffner, S. (2024). Thermodynamic perspective on quantum fluctuations.
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  What is the major difference between large and small systems? At smalllength-scales the dynamics is dominated by fluctuations, whereas at largescales fluctuations are irrelevant. Therefore, any thermodynamically consistentdescription of quantum systems necessitates a thorough understanding of thenature and consequences of fluctuations. In this chapter, we outline twoclosely related fields of research that are commonly considered separately --fluctuation forces and fluctuation theorems. Focusing on the main gist of theseexciting and vivid fields of modern research, we seek to provide a instructiveentry point for both communities of researchers interested in learning aboutthe other.[Journal_ref: ]
• Lee, A., Han, H. S., Fatemi, F. K., Rolston, S. L., & Sinha, K. (2023). Collective quantum beats from distant multilevel emitters. Phys. Rev. A, 107, 013701.
• Solano, P., Barberis-Blostein, P. .., & Sinha, K. (2023). Dissimilar collective decay and directional emission from two quantum emitters. Phys. Rev. A, 107, 023723.
• Olivera, A., Sinha, K., & Solano, P. (2022). Dipole-dipole interactions through a lens. Phys. Rev. A, 106, 013703.
• Sinha, K., & Goldschmidt, E. A. (2022). An atomic spin on amplification of light. Nature Photonics, 16(5), 339-340.
• Sinha, K., & Milonni, P. W. (2022). Dipoles in blackbody radiation: momentum fluctuations, decoherence, and drag force. Journal of Physics B: Atomic, Molecular and Optical Physics, 55(20), 204002.
• Sinha, K., Khan, S. A., C"uce, E., & T"ureci, H. E. (2022). Radiative properties of an artificial atom coupled to a Josephson-junction array. Phys. Rev. A, 106, 033714.
• Smith, A., Sinha, K., & Jarzynski, C. (2022). Quantum Coherences and Classical Inhomogeneities as Equivalent Thermodynamics Resources. Entropy, 24(4).
• Carney, D., Krnjaic, G., Moore, D. C., Regal, C. A., Afek, G., Bhave, S., Brubaker, B., Corbitt, T., Cripe, J., Crisosto, N., Geraci, A., Ghosh, S., Harris, J., Hook, A., Kolb, E. W., Kunjummen, J., Lang, R. F., Li, T., Lin, T., , Liu, Z., et al. (2021). Mechanical quantum sensing in the search for dark matter. Quantum Science and Technology, 6(2), 024002.
• Han, H. S., Lee, A., Sinha, K., Fatemi, F. K., & Rolston, S. L. (2021). Observation of Vacuum-Induced Collective Quantum Beats. Phys. Rev. Lett., 127, 073604.
• Sinha, K., L'opez, A., & fi{, Y. (2021). Dissipative dynamics of a particle coupled to a field via internal degrees of freedom. Phys. Rev. D, 103, 056023.
• Sinha, K., & fi{, Y. (2020). Quantum Brownian motion of a particle from Casimir-Polder interactions. Phys. Rev. A, 101, 032507.
• Sinha, K., Gonz'alez-Tudela, A., Lu, Y., & Solano, P. (2020). Collective radiation from distant emitters. Phys. Rev. A, 102, 043718.
• Sinha, K., Meystre, P., Goldschmidt, E. A., Fatemi, F. K., Rolston, S. L., & Solano, P. (2020). Non-Markovian Collective Emission from Macroscopically Separated Emitters. Phys. Rev. Lett., 124, 043603.
• Pino, H., Prat-Camps, J., Sinha, K., Venkatesh, B. P., & Romero-Isart, O. (2018). On-chip quantum interference of a superconducting microsphere. Quantum Science and Technology, 3(2), 025001.
• Sinha, K. (2018). Repulsive vacuum-induced forces on a magnetic particle. Phys. Rev. A, 97, 032513.
• Sinha, K., Venkatesh, B. P., & Meystre, P. (2018). Collective Effects in Casimir-Polder Forces. Phys. Rev. Lett., 121, 183605.
• Sinha, K., Lin, S., & Hu, B. L. (2015). Mirror-field entanglement in a microscopic model for quantum optomechanics. Phys. Rev. A, 92, 023852.
• Chang, D. E., Sinha, K., Taylor, J. M., & Kimble, H. J. (2014). Trapping atoms using nanoscale quantum vacuum forces. Nature Communications, 5(1), 4343.
• Sinha, K., Cummings, N. I., & Hu, B. L. (2012). Effect of interatomic separation on entanglement dynamics in a two-atom two-mode model. Journal of Physics B: Atomic, Molecular and Optical Physics, 45(3), 035503.
• Thyagarajan, K., Lugani, J., Ghosh, S., Sinha, K., Martin, A., Ostrowsky, D. B., Alibart, O., & Tanzilli, S. (2009). Generation of polarization-entangled photons using type-II doubly periodically poled lithium niobate waveguides. Phys. Rev. A, 80, 052321.

Proceedings Publications

• Sinha, K., Meystre, P., & Solano, P. (2019). Non-Markovian dynamics of collective atomic states coupled to a waveguide. In Quantum Nanophotonic Materials, Devices, and Systems 2019, 11091.
• Thyagarajan, K., Sinha, K., Lugani, J., Ghosh, S., Alibart, O., Ostrowsky, D. B., & Tanzilli, S. (2009). Generation of polarization entangled photons from type-II domain engineered PPLN waveguides. In Frontiers in Optics 2009/Laser Science XXV/Fall 2009 OSA Optics \& Photonics Technical Digest.