Showing 1–6 of 6 results for author: v orre

Tunable quantum interference using a topological source of indistinguishable photon pairs

Authors: Sunil Mittal, Venkata Vikram Orre, Elizabeth A. Goldschmidt, Mohammad Hafezi

Abstract: Sources of quantum light, in particular correlated photon pairs that are indistinguishable in all degrees of freedom, are the fundamental resource that enables continuous-variable quantum computation and paradigms such as Gaussian boson sampling. Nanophotonic systems offer a scalable platform for implementing sources of indistinguishable correlated photon pairs. However, such sources have so far r… ▽ More Sources of quantum light, in particular correlated photon pairs that are indistinguishable in all degrees of freedom, are the fundamental resource that enables continuous-variable quantum computation and paradigms such as Gaussian boson sampling. Nanophotonic systems offer a scalable platform for implementing sources of indistinguishable correlated photon pairs. However, such sources have so far relied on the use of a single component, such as a single waveguide or a ring resonator, which offers limited ability to tune the spectral and temporal correlations between photons. Here, we demonstrate the use of a topological photonic system comprising a two-dimensional array of ring resonators to generate indistinguishable photon pairs with dynamically tunable spectral and temporal correlations. Specifically, we realize dual-pump spontaneous four-wave mixing in this array of silicon ring resonators that exhibits topological edge states. We show that the linear dispersion of the edge states over a broad bandwidth allows us to tune the correlations, and therefore, quantum interference between photons by simply tuning the two pump frequencies in the edge band. Furthermore, we demonstrate energy-time entanglement between generated photons. We also show that our topological source is inherently protected against fabrication disorders. Our results pave the way for scalable and tunable sources of squeezed light that are indispensable for quantum information processing using continuous variables. △ Less

Submitted 20 January, 2021; v1 submitted 4 June, 2020; originally announced June 2020.

Comments: S.M. and V.V.O. contributed equally

Journal ref: Nature Photonics, 15, 542-548 (2021)

Interference of Temporally Distinguishable Photons Using Frequency-Resolved Detection

Authors: Venkata Vikram Orre, Elizabeth A. Goldschmidt, Abhinav Deshpande, Alexey V. Gorshkov, Vincenzo Tamma, Mohammad Hafezi, Sunil Mittal

Abstract: We demonstrate quantum interference of three photons that are distinguishable in time, by resolving them in the conjugate parameter, frequency. We show that the multiphoton interference pattern in our setup can be manipulated by tuning the relative delays between the photons, without the need for reconfiguring the optical network. Furthermore, we observe that the symmetries of our optical network… ▽ More We demonstrate quantum interference of three photons that are distinguishable in time, by resolving them in the conjugate parameter, frequency. We show that the multiphoton interference pattern in our setup can be manipulated by tuning the relative delays between the photons, without the need for reconfiguring the optical network. Furthermore, we observe that the symmetries of our optical network and the spectral amplitude of the input photons are manifested in the interference pattern. Moreover, we demonstrate time-reversed HOM-like interference in the spectral correlations using time-bin entangled photon pairs. By adding a time-varying dispersion using a phase modulator, our setup can be used to realize dynamically reconfigurable and scalable boson sampling in the time domain as well as frequency-resolved multiboson correlation sampling. △ Less

Submitted 24 September, 2019; v1 submitted 5 April, 2019; originally announced April 2019.

Journal ref: Phys. Rev. Lett. 123, 123603 (2019)

Photonic Anomalous Quantum Hall Effect

Authors: Sunil Mittal, Venkata Vikram Orre, Daniel Leykam, Y. D. Chong, Mohammad Hafezi

Abstract: We experimentally realize a photonic analogue of the anomalous quantum Hall insulator using a two-dimensional (2D) array of coupled ring resonators. Similar to the Haldane model, our 2D array is translation invariant, has zero net gauge flux threading the lattice, and exploits next-nearest neighbor couplings to achieve a topologically non-trivial bandgap. Using direct imaging and on-chip transmiss… ▽ More We experimentally realize a photonic analogue of the anomalous quantum Hall insulator using a two-dimensional (2D) array of coupled ring resonators. Similar to the Haldane model, our 2D array is translation invariant, has zero net gauge flux threading the lattice, and exploits next-nearest neighbor couplings to achieve a topologically non-trivial bandgap. Using direct imaging and on-chip transmission measurements, we show that the bandgap hosts topologically robust edge states. We demonstrate a topological phase transition to a conventional insulator by frequency detuning the ring resonators and thereby breaking the inversion symmetry of the lattice. Furthermore, the clockwise or the counter-clockwise circulation of photons in the ring resonators constitutes a pseudospin degree of freedom. We show that the two pseudospins acquire opposite hopping phases and their respective edge states propagate in opposite directions. These results are promising for the development of robust reconfigurable integrated nanophotonic devices for applications in classical and quantum information processing. △ Less

Submitted 1 April, 2019; originally announced April 2019.

Journal ref: Phys. Rev. Lett. 123, 043201 (2019)

Photonic quadrupole topological phases

Authors: Sunil Mittal, Venkata Vikram Orre, Guanyu Zhu, Maxim A. Gorlach, Alexander Poddubny, Mohammad Hafezi

Abstract: The topological phases of matter are characterized using the Berry phase, a geometrical phase, associated with the energy-momentum band structure. The quantization of the Berry phase, and the associated wavefunction polarization, manifest themselves as remarkably robust physical observables, such as quantized Hall conductivity and disorder-insensitive photonic transport. Recently, a novel class of… ▽ More The topological phases of matter are characterized using the Berry phase, a geometrical phase, associated with the energy-momentum band structure. The quantization of the Berry phase, and the associated wavefunction polarization, manifest themselves as remarkably robust physical observables, such as quantized Hall conductivity and disorder-insensitive photonic transport. Recently, a novel class of topological phases, called higher-order topological phases, were proposed by generalizing the fundamental relationship between the Berry phase and the quantized polarization, from dipole to multipole moments. Here, we demonstrate the first photonic realization of the quantized quadrupole topological phase, using silicon photonics. In this 2nd-order topological phase, the quantization of the bulk quadrupole moment in a two-dimensional system manifests as topologically robust corner states. We unambiguously show the presence of localized corner states and establish their robustness against certain defects. Furthermore, we contrast these topological states against topologically-trivial corner states, in a system without bulk quadrupole moment, and observe no robustness. Our photonic platform could enable the development of robust on-chip classical and quantum optical devices with higher-order topological protection. △ Less

Submitted 5 January, 2019; v1 submitted 21 December, 2018; originally announced December 2018.

Journal ref: Nature Photonics 13, 692-696 (2019)

Temporal and spectral manipulations of correlated photons using a time-lens

Authors: Sunil Mittal, Venkata Vikram Orre, Alessandro Restelli, Reza Salem, Elizabeth A. Goldschmidt, Mohammad Hafezi

Abstract: A common challenge in quantum information processing with photons is the limited ability to manipulate and measure correlated states. An example is the inability to measure picosecond scale temporal correlations of a multi-photon state, given state-of-the-art detectors have a temporal resolution of about 100 ps. Here, we demonstrate temporal magnification of time-bin entangled two-photon states us… ▽ More A common challenge in quantum information processing with photons is the limited ability to manipulate and measure correlated states. An example is the inability to measure picosecond scale temporal correlations of a multi-photon state, given state-of-the-art detectors have a temporal resolution of about 100 ps. Here, we demonstrate temporal magnification of time-bin entangled two-photon states using a time-lens, and measure their temporal correlation function which is otherwise not accessible because of the limited temporal resolution of single photon detectors. Furthermore, we show that the time-lens maps temporal correlations of photons to frequency correlations and could be used to manipulate frequency-bin entangled photons. This demonstration opens a new avenue to manipulate and analyze spectral and temporal wavefunctions of many-photon states. △ Less

Submitted 11 September, 2017; v1 submitted 14 April, 2017; originally announced April 2017.

Comments: Revised text and figures

Journal ref: Phys. Rev. A 96, 043807 (2017)

Topologically robust transport of entangled photons in a 2D photonic system

Authors: Sunil Mittal, Venkata Vikram Orre, Mohammad Hafezi

Abstract: We theoretically study the transport of time-bin entangled photon pairs in a two-dimensional topological photonic system of coupled ring resonators. This system implements the integer quantum Hall model using a synthetic gauge field and exhibits topologically robust edge states. We show that the transport through edge states preserves temporal correlations of entangled photons whereas bulk transpo… ▽ More We theoretically study the transport of time-bin entangled photon pairs in a two-dimensional topological photonic system of coupled ring resonators. This system implements the integer quantum Hall model using a synthetic gauge field and exhibits topologically robust edge states. We show that the transport through edge states preserves temporal correlations of entangled photons whereas bulk transport does not preserve these correlations and can lead to significant unwanted temporal bunching or anti-bunching of photons. We study the effect of disorder on the quantum transport properties; while the edge transport remains robust, bulk transport is very susceptible, and in the limit of strong disorder, bulk states become localized. We show that this localization is manifested as an enhanced bunching/anti-bunching of photons. This topologically robust transport of correlations through edge states could enable robust on-chip quantum communication channels and delay lines for information encoded in temporal correlations of photons. △ Less

Submitted 1 August, 2016; v1 submitted 16 May, 2016; originally announced May 2016.

Comments: Revised version

Journal ref: Optics Express, Vol. 24, Issue 14, pp. 15631-15641, 2016