Guanyu Zhu

IBM Research · Thomas J. Watson Research Center

We investigate the relationship between superselection rules and quantum error correcting codes. We demonstrate that the existence of a superselection rule implies the Knill-Laflamme condition in quantum error correction. As an example, we examine quantum chromodynamics through the lens of quantum error correction, where the proton and neutron stat...

Subsystem quantum error-correcting codes typically involve measuring a sequence of non-commuting parity check operators. They can sometimes exhibit greater fault-tolerance than conventional subspace codes, which use commuting checks. However, unlike subspace codes, it is unclear if subsystem codes -- in particular their advantages -- can be underst...

Online microwave drying process monitoring has been challenging due to the incompatibility of metal components with microwaves. This paper developed a microwave drying system based on online machine vision, which realized real-time extraction and measurement of images, weight, and temperature. An image-processing algorithm was developed to capture...

We study fault-tolerant error correction in a quantum memory constructed as a two-dimensional model of Fibonacci anyons on a torus, in the presence of thermal noise represented by pair-creation processes and measurement errors. The correction procedure is based on the cellular automaton decoders originating in the works of G\'acs and Harrington. Th...

We investigate topological order on fractal geometries embedded in n dimensions. We consider the n-dimensional lattice with holes at all length scales the corresponding fractal (Hausdorff) dimension of which is DH=n−δ. In particular, we diagnose the existence of the topological order through the lens of quantum information and geometry, i.e., via i...

We consider a two-dimensional quantum memory of qubits on a torus which encode the extended Fibonacci string-net code and devise strategies for error correction when those qubits are subjected to depolarizing noise. Building on the concept of tube algebras, we construct a set of measurements and of quantum gates which map arbitrary qubit errors to...

Strategies of far infrared drying (FID) and far infrared combined with hot air drying (FIHAD) were employed to preserve the quality of Anoectochilus. It was dried with four different drying temperatures (50, 60, 70 and 80 °C) under FID and three different drying temperatures (50, 60, and 70 °C) under FIHAD. After drying, drying kinetics, color, and...

We study the error threshold properties of holographic quantum error-correcting codes. We demonstrate that holographic CFTs admit an algebraic threshold, which is related to the confinement-deconfinement phase transition. We then apply geometric intuition from holography and the Hawking-Page phase transition to motivate the CFT result, and comment...

Recently, a class of fractal surface codes (FSCs), has been constructed on fractal lattices with Hausdorff dimension $2+\epsilon$, which admits a fault-tolerant non-Clifford CCZ gate. We investigate the performance of such FSCs as fault-tolerant quantum memories. We prove that there exist decoding strategies with non-zero thresholds for bit-flip an...

We investigate topological order on fractal geometries embedded in $n$ dimensions. In particular, we diagnose the existence of the topological order through the lens of quantum information and geometry, i.e., via its equivalence to a quantum error-correcting code with a macroscopic code distance or the presence of macroscopic systoles in systolic g...

We consider a two-dimensional quantum memory of qubits on a torus which encode the extended Fibonacci string-net code, and devise strategies for error correction when those qubits are subjected to depolarizing noise. Building on the concept of tube algebras, we construct a set of measurements and of quantum gates which map arbitrary qubit errors to...

The influence of relative humidity of hot air on the finger citron slices drying characteristics, properties and aroma during microwave drying process was investigated. A new microwave drying system with relative humidity control was developed. Three levels of relative humidity of hot air, 20%, 40%, 60% of material with the temperature of 70 ºC wer...

We study quasi-exact quantum error-correcting codes and quantum computation with them. A quasi-exact code is an approximate code such that it contains a finite number of scaling parameters, the tuning of which can flow it to corresponding exact codes, serving as its fixed points. The computation with a quasi-exact code cannot realize any logical ga...

Instantly sensing the food quality attributes is a prerequisite to regulate the drying process for final product quality improvement. Novel sensing technologies have been “pushed” to food drying engineering from other research disciplines. Electronic nose, computer vision, hyperspectral imaging, near-infrared, nuclear magnetic resonance, and dielec...

The color code is a topological quantum error-correcting code supporting a variety of valuable fault-tolerant logical gates. Its two-dimensional version, the triangular color code, may soon be realized with currently available superconducting hardware despite constrained qubit connectivity. To guide this experimental effort, we study the storage th...

In this work we introduce two code families, which we call the heavy-hexagon code and the heavy-square code. Both code families are implemented by assigning physical data and ancilla qubits to both vertices and edges of low-degree graphs. Such a layout is particularly suitable for superconducting qubit architectures to minimize frequency collisions...

A real-time aroma monitoring system to control a microwave combined with hot air drying (MHAD) process of carrot was designed. The samples were first dried at four fixed temperature gradients of 2°C/mm, 4°C/mm, 6°C/mm and 8°C/mm to investigate the effect of temperature gradient on the aroma diffusion. Carrot samples could be dried in a shorter time...

A real-time aroma-detecting system for carrot processing through microwave combined with hot-air drying was constructed to study the aroma diffusion and quality of carrots by controlling the material temperature and temperature differences between material core and hot air. Various pairs of material temperatures (60 °C, 70 °C, 80 °C) and temperatur...

The color code is a topological quantum error-correcting code supporting a variety of valuable fault-tolerant logical gates. Its two-dimensional version, the triangular color code, may soon be realized with currently available superconducting hardware despite constrained qubit connectivity. To guide this experimental effort, we study the storage th...

The article investigates comparative experimental results and analysis of three drying stratagems, namely, infrared (IR), hot‐air (HA), and combination of IR and HA (IR‐HA), on the drying characteristics, ginsenosides, and sensory properties of ginseng root slices. The three drying tests were conducted at 50, 60, and 70°C, and the IR power was moni...

We study quasi-exact quantum error correcting codes and quantum computation with them. Here `quasi-exact' means it becomes the same as the exact cases under proper limits. We find that the tradeoff between universality and transversality of the set of quantum gates, due to Eastin and Knill, does not persist in the quasi-exact scenario. A class of c...

Quantum information scrambling has attracted much attention amid the effort to reconcile the conflict between quantum-mechanical unitarity and the thermalization irreversibility in many-body systems. Here we propose an unconventional mechanism to generate quantum information scrambling through a high-complexity mapping from logical to physical degr...

In this work we introduce two code families, which we call the heavy hexagon code and heavy square code. Both code families are implemented by assigning physical data and ancilla qubits to both vertices and edges of low degree graphs. Such a layout is particularly suitable for superconducting qubit architectures to minimize frequency collision and...

Recently, quantum information scrambling has attracted much attention amid the effort to reconcile the apparent conflict between quantum-mechanical unitarity and the irreversibility of thermalizaiton in quantum many-body systems. Here we propose an unconventional mechanism to generate quantum information scrambling through a high-complexity mapping...

Fresh carrot cubes were blanched and dried by microwave processing combined with hot air drying. Material temperature, temperature difference and size of cube were optimised in terms of total vitamin C content, colour change, drying time, sensory evaluation and rehydration ratio of dried samples. During a stage under the optimal drying condition, d...

This study was conducted to optimize the drying process of Polygonum cuspidatum slices using an orthogonal experimental design. The combined effects of pretreatment methods, vacuum pressure and temperature of inner material, drying kinetics, color value, and retention of the indicator compounds were investigated. Seven mathematical models on thin-l...

The problem of interacting bosons in frustrated lattices is an intricate one due to the absence of a unique minimum in the single-particle dispersion where macroscopic number of bosons can condense. Here, we consider a family of tight-binding models with macroscopically degenerate lowest energy bands, separated from other bands by a gap. We predict...

We consider a family of tight-binding models based on kagome lattice with local fluxes, which have a lowest flat band in the single particle spectrum. The flat band is spanned by eigenstates forming localized loops on the lattice, with the maximally compact loop states typically breaking the discrete rotational symmetry of the lattice. When populat...

Photon-based strongly-correlated lattice models like the Jaynes-Cummings and Rabi lattices differ from their more conventional relatives like the Bose-Hubbard model by the presence of an additional tunable parameter: the frequency detuning between the pseudo-spin degree of freedom and the harmonic mode frequency on each site. Whenever this detuning...

In charge-coupled circuit QED systems, transition amplitudes and dispersive shifts are governed by the matrix elements of the charge operator. For the fluxonium circuit, these matrix elements are not limited to nearest-neighbor energy levels and are conveniently tunable by magnetic flux. Previously, their values were largely obtained numerically. H...

In circuit QED, protocols for quantum gates and readout of superconducting qubits often rely on the dispersive regime, reached when the qubit-photon detuning {\Delta} is large compared to their mutual coupling strength. For qubits including the Cooper-pair box and transmon, selection rules dramatically restrict the contributions to dispersive level...

Manipulation and readout of superconducting qubits with microwave photons, as realized in circuit QED, commonly employ the dispersive regime. In this regime, the qubit-photon interaction strength is small compared to the relative detuning delta, and manifests itself only in the dispersive energy shifts chi, crucial for dispersive readout and spectr...