Publications

The quantum SWITCH is an example of a process with an indefinite causal structure, and has attracted attention for its ability to …

It is an important question to find constructions of quantum cryptographic protocols which rely on weaker computational assumptions …

We report on the characterization of a SiGe PIC-based receiver along with its usage in a Gaussian-modulated coherent state CV-QKD …

Quantum threshold theorems impose hard limits on the hardware capabilities to process quantum information. We derive tight and …

Standard Bell inequalities hold when distant parties are not allowed to communicate. Barrett et al. found correlations from Pauli …

The security of modern communication networks can be enhanced thanks to the laws of quantum mechanics. In this thesis, we develop a …

Many applications of quantum computing in the near term rely on variational quantum circuits (VQCs). They have been showcased as a …

Physical unclonable functions(PUFs) provide a unique fingerprint to a physical entity by exploiting the inherent physical randomness. …

With the recent availability of cloud quantum computing services, the question of verifying quantum computations delegated by a client …

In the macroscopic world, time is intrinsically asymmetric, flowing in a specific direction, from past to future. However, the same is …

As in modern communication networks, the security of quantum networks will rely on complex cryptographic tasks that are based on a …

Differential privacy provides a theoretical framework for processing a dataset about n users, in a way that the output reveals a …

We present the architecture and analyze the applications of a metropolitan-scale quantum network that requires only limited hardware …

We introduce a secure hardware device named a QEnclave that can secure the remote execution of quantum operations while only using …

The subset cover problem for $k \geq 1$ hash functions, which can be seen as an extension of the collision problem, was introduced in …

The traditional definition of quantum zero-knowledge stipulates that the knowledge gained by any quantum polynomial-time verifier in an …

It is well known that the effect of quantum nonlocality, as witnessed by violation of a Bell inequality, can be observed even when …

Future quantum internet aims to enable quantum communication between arbitrary pairs of distant nodes through the sharing of end-to-end …

While the standard formulation of quantum theory assumes a fixed background causal structure, one can relax this assumption within the …

The problem of private learning has been extensively studied in classical computer science. Notably, a striking equivalence between …

Networks of quantum sensors are a central application of burgeoning quantum networks. A key question for the use of such networks will …

Future quantum internet aims to enable quantum communication between arbitrary pairs of distant nodes through the sharing of end-to-end …

This paper, for the first time, addresses the questions related to the connections between quantum pseudorandomness and quantum …

We introduce a family of ZX-calculi which axiomatise the stabiliser fragment of quantum theory in odd prime dimensions. These calculi …

Quantum theory allows for nonlocality without entanglement. Notably, there exist bipartite quantum measurements consisting of only …

Quantum computers promise surprising powers of computation by exploiting the stunning physical properties of infinitesimally small …

The thesis is divided into two parts: The first part is in the field of Quantum Cryptography. In this part we develop a theoretical …

Quantum key distribution offers the possibility of cryptography whose security is demonstrated by the laws of quantum physics. The …

Quantum key distribution offers the possibility of cryptography whose security is demonstrated by the laws of quantum physics. The …

Quantum Information Networks (QIN) currently represent a major goal in the field quantum communication technologies. Such QINs will …

Measurement-based quantum computation (MBQC) is an alternative model for quantum computation, which makes careful use of the properties …

Authentication of quantum sources is a crucial task in building reliable and efficient protocols for quantum-information processing. …

Abstract Integrated photonics will play a key role in quantum systems as they grow from few-qubit prototypes to tens of thousands of …

Quantum computers will provide considerable speedups with respect to their classical counterparts. However, the identification of the …

A quantum metrology scheme can be decomposed into three quantum tasks: state preparation, parameter encoding and measurements. …

Information-theoretic lower bounds are often encountered in several branches of computer science, including learning theory and …

Quantum metrology is an auspicious discipline of quantum information which is currently witnessing a surge of experimental …

In the last decade a lot of research activity focused on the use of quantum entanglement as a resource for remote target detection, …

The field of quantum networks is currently a major area of investigation in quantum technologies. One of the simplest acts of quantum …

The random oracle model (ROM) enjoys widespread popularity, mostly because it tends to allow for tight and conceptually simple proofs …

We study continuous-variable graph states as quantum communication networks. We explore graphs with regular and complex network shapes …

We study here the conditions to perform the distribution of a pure state on a quantum network using quantum operations which can …

Recently, there has been an emergence of useful applications for noisy intermediate-scale quantum (NISQ) devices notably, though not …

Due to the special no-cloning principle, quantum states appear to be very useful in cryptography. But this very same property also has …

Correcting errors due to noise in quantum circuits run on current and near-term quantum hardware is essential for any convincing …

Quantum physical unclonable functions, or QPUFs, are rapidly emerging as theoretical hardware solutions to provide secure cryptographic …

In this paper, we continue the line of work initiated by Boneh and Zhandry at CRYPTO 2013 and EUROCRYPT 2013 in which they formally …

Graph states are a large class of multipartite entangled quantum states that form the basis of schemes for quantum computation, …

Approximate combinatorial optimisation has emerged as one of the most promising application areas for quantum computers, particularly …

Future quantum communication infrastructures will rely on both terrestrial and space-based links integrating high-performance optical …

The demonstration of quantum speedup, also known as quantum computational supremacy, that is the ability of quantum computers to …

We introduce a secure hardware device named a QEnclave that can secure the remote execution of quantum operations while only using …

Physical unclonable functions provide a unique ‘fingerprint’ to a physical entity by exploiting the inherent physical …

The use of quantum information in technology promises to supersede the so-called classical devices used nowadays. Understanding what …

Quantum physics has revolutionised our way of conceiving nature and is now bringing about a new technological revolution. The use of …

The development of large-scale quantum networks promises to bring a multitude of technological applications as well as shed light on …

MiniQCrypt is a world where quantum-secure one-way functions exist, and quantum communication is possible. We construct an oblivious …

In measurement-based quantum computing (MBQC), computation is carried out by a sequence of measurements and corrections on an entangled …

We designed a CV-QKD system with off-the-shelf components and established the feasibility of distributing 67.6 and 66.8 Mb/s secret key …

While the standard formulation of quantum theory assumes a fixed background causal structure, one can relax this assumption within the …

Abstract Quantum communication networks enable applications ranging from highly secure communication to clock synchronization and …

Quantum cryptography builds upon decades of advances both in classical cryptography and networks. However, contrary to its classical …

We consider Gaussian quantum circuits supplemented with non-Gaussian input states and derive sufficient conditions for efficient …

We study supervised learning algorithms in which a quantum device is used to perform a computational subroutine - either for prediction …

Recently, the European Commission supported by many European countries has announced large investments towards the commercialization of …

We propose a method to experimentally demonstrate contextuality with a family of tests for qudits. The experiment we propose uses a …

This work analyzes correlations arising from quantum systems subject to sequential projective measurements to certify that the system …

Negativity of the Wigner function is arguably one of the most striking non-classical features of quantum states. Beyond its fundamental …

We demonstrate, for the first time to our knowledge, continuous-variable quantum key distribution using probabilistically-shaped …

We derive a theoretical framework for the experimental certification of non-Gaussian features of quantum states using double homodyne …

We present a composably secure protocol allowing $n$ parties to test an entanglement generation resource controlled by a possibly …

In measurement-based quantum computing (MBQC), computation is carried out by a sequence of measurements and corrections on an entangled …

Noise is the greatest obstacle in quantum metrology that limits it achievable precision and sensitivity. There are many techniques to …

Configurable and scalable continuous variable quantum networks for measurement-based quantum information protocols or multipartite …

Multi-Party Quantum Computation (MPQC) has attracted a lot of attention as a potential killer-app for quantum networks through …

This thesis is concerned with the study and analysis of two quantum cryptographic protocols: quantum key distribution (QKD) and …

In recent years, many computational tasks have been proposed as candidates for showing a quantum computational advantage, that is an …

The implementation of a quantum internet requires the distribution of entanglement over long distances, which is facilitated by …

The application and analysis of the Cut-and-Choose technique in protocols secure against quantum adversaries is not a straightforward …

In this note, we analyze joint probability distributions that come from the outcomes of quantum measurements performed on sets of …

Despite the interest in the complexity class MA, the randomized analog of NP, just a few natural MA-complete problems are known. The …

Cryptanalysis on standard quantum cryptographic systems generally involves finding optimal adversarial attack strategies on the …

Secure two-party computation considers the problem of two parties computing a joint function of their private inputs without revealing …

In order to qualify quantum algorithms for industrial NP-Hard problems, comparing them to available polynomial approximate classical …

Recently, major progress has been made towards the realisation of the quantum internet to enable a broad range of applications that …

Generative Modelling has become a promising use case for near term quantum computers. In particular, due to the fundamentally …

Establishing secure communication links at a global scale is a major potential application of quantum information science but also …

Research on quantum technology spans multiple disciplines: physics, computer science, engineering, and mathematics. The objective of …

Finding a concrete use case for quantum computers in the near term is still an open question, with machine learning typically touted as …

Secure delegated quantum computing allows a computationally weak client to outsource an arbitrary quantum computation to an untrusted …

We propose a learning model called the quantum statistical learning QSQ model, which extends the SQ learning model introduced by Kearns …

We establish the first general connection between the design of quantum algorithms and circuit lower bounds. Specifically, let …

It is of folkloric belief that the security of classical cryptographic protocols is automatically broken if the Adversary is allowed to …

Random access codes have provided many examples of quantum advantage in communication, but concern only one kind of information …

Recent experimental achievements motivate an ever-growing interest from companies starting to feel the limitations of classical …

We provide several advances to the understanding of the class of Quantum Merlin-Arthur proof systems (QMA), the quantum analogue of NP. …

In a recent breakthrough, Mahadev constructed an interactive protocol that enables a purely classical party to delegate any quantum …

StoqMA characterizes the computational hardness of stoquastic local Hamiltonians, which is a family of Hamiltonians that does not …

Authenticated teleportation aims to certify the transmission of a quantum state through teleportation, even in the presence of an …

Recent works revealed that transmission of light beams carrying orbital-angular-momentum (OAM) through turbulence causes the optical …

A defining feature in the field of quantum computing is the potential of a quantum device to outperform its classical counterpart for a …

Weak coin flipping is among the fundamental cryptographic primitives which ensure the security of modern communication networks. It …

The theory of the asymptotic manipulation of pure bipartite quantum systems can be considered completely understood: the rates at which …

Instantaneous nonlocal quantum computation (INQC) evades apparent quantum and relativistic constraints and allows to attack generic …

Quantum physics has led to a revolution in our conception of the nature of our world and is now bringing about a technological …

Quantum physics has led to a revolution in our conception of the nature of our world and is now bringing about a technological …

The search for an application of near-term quantum devices is widespread. Quantum machine learning is touted as a potential utilisation …

Concomitant with the rapid development of quantum technologies, challenging demands arise concerning the certification and …

By using highly entangled states, quantum metrology guarantees precision impossible with classical measurements. Unfortunately such …

The so-called stellar formalism allows to represent the non-Gaussian properties of single-mode quantum states by the distribution of …

We present a simple protocol for certifying graph states in quantum networks using stabiliser measurements. The certification …

Quantum key distribution (QKD) is one of the first quantum technologies that were able to provide commercially meaningful solutions to …

Physical Unclonable Functions (PUFs) are physical devices with unique behavior that are hard to clone. A variety of PUF schemes have …

The functionality of classically-instructed remotely prepared random secret qubits was introduced in (Cojocaru et al 2018) as a way to …

Quantum metrology is a promising practical use case for quantum technologies, where physical quantities can be measured with …

Multipartite entangled states are great resources for quantum networks. In this work we study the distribution, or routing, of …

This thesis is focused on the generation and understanding of particular kinds of quantum randomness. Randomness is useful for many …

In this work we reduce the requirements for generating $t$-designs, an important tool for randomisation with applications across …

As research on building scalable quantum computers advances, it is important to be able to certify their correctness. Due to the …

We prove a conjecture due to Wanless about the permanent of Hadamard matrices in the particular case of Sylvester-Hadamard matrices. …

We introduce a protocol for authenticated teleportation, which can be proven secure even when the receiver does not trust their …

In August 2015 the cryptographic world was shaken by a sudden and surprising announcement by the US National Security Agency NSA …

We consider a protocol for sharing quantum states using continuous variable systems. Specifically we introduce an encoding procedure …

Blind delegation protocols allow a client to delegate a computation to a server so that the server learns nothing about the input to …

The search for an application of near-term quantum devices is widespread. Quantum Machine Learning is touted as a potential utilisation …

We establish a lower bound on the asymptotic secret key rate of continuous-variable quantum key distribution with a discrete modulation …

Contextuality is a non-classical behaviour that can be exhibited by quantum systems. It is increasingly studied for its relationship to …

Quantum communication networks have the potential to revolutionize information and communication technologies. Here we are interested …

At its core a $t$-design is a method for sampling from a set of unitaries in a way which mimics sampling randomly from the Haar measure …

The no-cloning property of quantum mechanics allows unforgeability of quantum banknotes and credit cards. Quantum credit card protocols …

Continuous-Variable (CV) devices are a promising platform for demonstrating large-scale quantum information protocols. In this …

We present a scheme for a universal device which can be programed by quantum states to approximate a chosen projective measurement to a …

With experimental quantum computing technologies now in their infancy, the search for efficient means of testing the correctness of …

Demonstrating quantum superiority for some computational task will be a milestone for quantum technologies and would show that …

We define the functionality of delegated pseudo-secret random qubit generator (PSRQG), where a classical client can instruct the …

Recent advances at Google, IBM, as well as a number of research groups indicate that quantum computers will soon be reality. Motivated …

The intrinsic non-locality of correlations in Quantum Mechanics allow us to certify the behaviour of a quantum mechanism in a device …

Models of quantum systems on curved space-times lack sufficient experimental verification. Some speculative theories suggest that …

We experimentally show how multiband dispersion properties of inhibited-coupling hollow-core fibers allow to control the spectral …

Quantum computing is emerging at a meteoric pace from a pure academic field to a fully industrial framework. Rapid advances are …

Steering, a quantum property stronger than entanglement but weaker than non-locality in the quantum correlation hierarchy, is a key …

In this work, we demonstrate a way to perform classical multiparty computing among parties with limited computational resources. Our …

Blind quantum computing (BQC) allows a client to have a server carry out a quantum computation for them such that the client’s …

The universal blind quantum computation protocol (UBQC) enables an almost classical client to delegate a quantum computation to an …

Recent developments have brought the possibility of achieving scalable quantum networks and quantum devices closer. From the …

The relationship between correlations and entanglement has played a major role in understanding quantum theory since the work of …

Secure communication is emerging as a significant challenge for our hyper-connected data-dependent society. The answer may lie in a …

We have theoretically investigated the possibility of using any of several continuous-variable Bell-type inequalities - for which the …

With the development of delegated quantum computation, clients will want to ensure confidentiality of their data and algorithms, and …

We introduce a simple single-system game inspired by the Clauser-Horne-Shimony-Holt (CHSH) game. For qubit systems subjected to unitary …

The transversely confined propagating modes of an optical fiber mediate virtually infinite range energy exchanges among atoms placed …

Electronic voting is a very useful but challenging internet-based protocol that despite many theoretical approaches and various …

We introduce a notion of contextuality for transformations in sequential contexts, distinct from the Bell-Kochen-Specker and Spekkens …

We consider a device which can be programed using coherent states of light to approximate a given projective measurement on an input …

Mistrustful cryptography includes important tasks like bit commitment, oblivious transfer, coin flipping, secure computations, position …

Spectro-temporal modes of light can be exploited for the generation of high-dimensional Gaussian quantum states. Such states are at the …

The network structure offers in principle the possibility for novel forms of quantum nonlocal correlations, that are proper to networks …

Photonic quantum technologies represent a promising platform for applications ranging from long-distance secure communications to the …

Multi-plane light conversion allows to perform arbitrary transformations on a finite set of spatial modes with no theoretical …

Wiesner’s unforgeable quantum money scheme is widely celebrated as the first quantum information application. Based on the …

Demonstrating a quantum advantage with currently available experimental systems is of utmost importance in quantum information science. …

We investigate the impact of Hilbert-space truncation upon the entanglement of an initially maximally entangled m × m bipartite quantum …

We consider a cryptographically motivated framework for quantum metrology in the presence of a malicious adversary. We begin by …

We present a general framework encompassing a number of continuous-variable quantum key distribution protocols, including standard …

The generation of certifiable randomness is one of the most promising applications of quantum technologies. Furthermore, the intrinsic …

We first introduce heterodyne quantum state tomography, a reliable method for continuous variable quantum state certification which …

Quantum network protocols offer new functionalities such as enhanced security to communication and computational systems. Despite the …

We demonstrate theoretically and experimentally a high level of control of the four-wave mixing process in an inert gas–filled …