Massachusetts Institute of Technology

Columbia University

Jacob C Mower

Dirk Robert Englund

Nicholas Christopher Harris

Greg Steinbrecher

Karl Kimon Berggren

Seth Lloyd

Mikkel Heuck

Xiaolong Hu

Faraz Najafi

Pierre Desjardins

Jelena Notaros

Cosmo Lupo

A programmable photonic integrated circuit implements arbitrary linear optics transformations in the spatial mode basis with high fidelity. Under a realistic fabrication model, we analyze programmed implementations of the CNOT gate, CPHASE gate, iterative phase estimation algorithm, state preparation, and quantum random walks. We find that programmability dramatically improves device tolerance to fabrication imperfections and enables a single device to implement a broad range of both quantum and classical linear optics experiments. Our results suggest that existing fabrication processes are sufficient to build such a device in the silicon photonics platform.

Programmable photonic processing

A large-scale tunable-coupling ring array includes an input waveguide coupled to multiple ring resonators, each of which has a distinct resonant wavelength. The collective effect of these multiple ring resonators is to impart a distinct time delay to a distinct wavelength component (or frequency component) in an input signal, thereby carrying out quantum scrambling of the input signal. The scrambled signal is received by a receiver also using a large-scale tunable-coupling ring array. This receiver-end ring resonator array recovers the input signal by imparting a compensatory time delay to each wavelength component. Each ring resonator can be coupled to the input waveguide via a corresponding Mach Zehnder interferometer (MZI). The MZI includes a phase shifter on at least one of its arms to increase the tunability of the ring array.

Apparatus and methods for locked quantum communication using photonic integrated circuits

Methods, systems, and apparatus for programmable quantum photonic processing

Techniques for temporal quantum key distribution between at least a first entity and a second entity include measuring an arrival time of each of a plurality of photons within each of a set of time frames. The arrival time can correspond to one of the plurality of time bins within the time frame. Measuring can occur in a randomly selected one of at least two mutually unbiased bases. The mutually unbiased bases can include a basis corresponding to a measurement with dispersion and a basis corresponding to a measurement without dispersion. The randomly selected basis for each time frame can be communicated, via a classical communications channel. A quantum key can be generated from the time bins corresponding to the arrival time of photons within at least some of the time frames for which the randomly selected basis is consistent between the first and the second entity.

Systems and methods for telecommunication using high-dimensional temporal quantum key distribution

Techniques for converting signal and idler photons generated by a nonlinear optical system into a deterministic stream of single photons including receiving a heralded, nondeterministic source of signal and idler photons from the nonlinear optical process, separating one or more received signal photons from one or more received temporally corresponding idler photons, determining whether at least one of the one or more signal photons should be variably delayed, and if so, determining a delay length, and variably delaying the emission of one of the one or more signal photons, if any, by the determined delay length.

Chip integrated single photon generation by active time multiplexing

Compactly-integrated electronic structures and associated systems and methods are provided. Certain embodiments relate to the ability to integrate nanowire-based detectors with optical components.

Compactly-integrated optical detectors and associated systems and methods

A method for distributing a quantum key is provided, including sending a first photon to a first receiver; sending a second photon to a second receiver, the first and second photons being a pair of time-energy entangled photons; and providing a coding scheme comprising a plurality of time bins and a plurality of frequency bins, wherein a combination of a time bin and a frequency bin corresponds to a character.

Growing community of inventors

Cambridge, MA, United States of America

Jacob C Mower