QuCSI

Virtual Quantum Resource Distillation (Phys. Rev. Lett. 132, 050203)

Ideal quantum resources, such as Bell States for Entanglement or Magic States of quantum error corrections, are ket to enable useful quantum technologies. However, in many instances, experimental imperfections make it impossible to engineer such states exactly. Quantum resource distillation represents a class protocol aimed to remedy this, converting many copies of imperfect quantum states ... Read moreVirtual Quantum Resource Distillation (Phys. Rev. Lett. 132, 050203)

Quantum-optimal information encoding using noisy passive linear optics (Quantum 8, 1218)

Determining the maximal amount of information that can be reliably transmitted through a noisy channel is a key question in information theory. This study delves into a class of optical quantum channels that stand out for their practicality: they do not require an external energy source for their operation. By focusing on these channels, the ... Read moreQuantum-optimal information encoding using noisy passive linear optics (Quantum 8, 1218)

Universal Sampling Lower Bounds for Quantum Error Mitigation (Phys. Rev. Lett. 131, 210602)

Quantum computing holds tremendous promise but is hindered by the pervasive influence of noise on the delicate quantum states. Various strategies have been devised to mitigate these errors in the absence of error correction, yet it remains unclear when such methods are sufficient. Here, we consider the fundamental sampling cost, i.e., the number of iterations ... Read moreUniversal Sampling Lower Bounds for Quantum Error Mitigation (Phys. Rev. Lett. 131, 210602)

Quantum Uncertainty Principles for Measurements with Interventions (Phys. Rev. Lett. 130, 240201)

Interactive measurements represent the most powerful way in which agents can learn about their environments. When toddlers want to understand cause and effect for example, they don't merely observe. Instead they try different actions, and observe the reactions. This interactivity is key to learning the causal relations between objects. As such, in Artificial intelligence and ... Read moreQuantum Uncertainty Principles for Measurements with Interventions (Phys. Rev. Lett. 130, 240201)

Implementing quantum dimensionality reduction for non-Markovian stochastic simulation (Nat Commun 14, 2624)

Complex systems such as traffic patterns weather forecasts, and financial markets are ‘stochastic’ processes typically modelled by storing vast amounts of information about events in the past – which quickly consumes lots of memory. The downside of of this is not only resource cost. The more things a model tracks, the harder it is to ... Read moreImplementing quantum dimensionality reduction for non-Markovian stochastic simulation (Nat Commun 14, 2624)

Fundamental limits of quantum error mitigation (npj Quantum Inf 8, 114)

The unavoidable accumulation of errors in quantum devices is consider a key hurdle in unlocking the full potential of quantum computing. In this, current generation quantum computers cannot do adaptive error correction and are thus limited to error-mitigation - a process of supressing errors without actively making measurements and adapting computation to their outcomes.  Here ... Read moreFundamental limits of quantum error mitigation (npj Quantum Inf 8, 114)

Thermodynamic machine learning through maximum work production (New J. Phys. 24 083040)

Adaptive systems, ranging from living organisms to autonomous robots, exhibit the ability to thrive by effectively utilizing the resources in their environments. Often this requires learning models of their environment, such that the agent can best understand what to anticipate in the future depending on past expereincces. However, such adaptive systems are physical, and so ... Read moreThermodynamic machine learning through maximum work production (New J. Phys. 24 083040)

Optimal Gain Sensing of Quantum-Limited Phase-Insensitive Amplifiers (Phys. Rev. Lett. 128, 180506)

While significant work has been done in understanding how non-classical optical probes and enhance our ability to measure and detect loss in a channel, far less has been done about measuring gain. Here we focus on Phase-insensitive optical amplifiers that amplify input light-beams in a way that is phase-independent. We showed that unlike in the ... Read moreOptimal Gain Sensing of Quantum-Limited Phase-Insensitive Amplifiers (Phys. Rev. Lett. 128, 180506)

Space-efficient optical computing with an integrated chip diffractive neural network (Nat Commun 13, 1044)

Optical neural networks (ONNs) are a rapidly developing field of technology that uses light to perform complex computing tasks. Until now, most ONNs have been large and power-hungry, limiting their practical use. Traditional approaches rely on units called Mach-Zehnder interferometers (MZIs) for their calculations. For large-scale computations, this approach can require an excessive amount of units ... Read moreSpace-efficient optical computing with an integrated chip diffractive neural network (Nat Commun 13, 1044)

Characterizing correlation within multipartite quantum systems via local randomized measurements

Given a quantum system on many qubits split into a few different parties, how many total correlations are there between these parties? Such a quantity, aimed to measure the deviation of the global quantum state from an uncorrelated state with the same local statistics, plays an important role in understanding multipartite correlations within complex networks ... Read moreCharacterizing correlation within multipartite quantum systems via local randomized measurements