Bulletin of the American Physical Society
APS March Meeting 2023
Volume 68, Number 3
Las Vegas, Nevada (March 5-10)
Virtual (March 20-22); Time Zone: Pacific Time
Session Z02: Experimental Advances and Open Quantum Systems in the Thermodynamic Regime |
Hide Abstracts |
Sponsoring Units: GSNP DQI Chair: Gabriel Landi, University of Rochester Room: Room 125 |
Friday, March 10, 2023 11:30AM - 11:42AM |
Z02.00001: Experimental observation of thermalisation with noncommuting charges Aleksander A Lasek, Florian Kranzl, Manoj K Joshi, Amir Kalev, Rainer Blatt, Christian Roos, Nicole Y Halpern Noncommuting charges have recently emerged as an area at the intersection of quantum thermodynamics and quantum information. There is a flurry of papers being published in this rapidly developing subfield. Often, the global energy and particle number are conserved, and the system is prepared with a well-defined particle number. However, quantum evolution can also conserve quantities, or charges, that fail to commute with each other. As noncommutation underlies quantumness, such systems are of particular interest. Quantum simulators have recently enabled experimental observations of quantum many-body systems' internal thermalisation. We initiate the experimental testing of its predictions with a trapped-ion simulator. We initialize 6–21 qubits in an approximate microcanonical subspace, a recently theorized generalisation of the microcanonical subspace for accommodating noncommuting charges. The noncommuting charges are the three spin components. We report the first experimental observation of an equilibrium state predicted within quantum-information thermodynamics in 2016: the non-Abelian thermal state. Despite the threat of decoherence breaking multiple conservation laws, thanks to our use of dynamical decoupling, our many-body system is shown to exhibit quantum-thermodynamical effects only described in theory until now. This work initiates the experimental testing of a recently emerged subfield that has so far remained theoretical. |
Friday, March 10, 2023 11:42AM - 11:54AM |
Z02.00002: Measurement-driven quantum clock implemented with a superconducting qubit Xin HE, Prasanna Pakkiam, Adil Gangat, Gerard Milburn, Arkady Fedorov We demonstrate a quantum clock implemented with a superconducting transmon qubit dispersively coupled to an open co-planar resonator for qubit state readout. The cavity and qubit are driven by coherent fields and readout resonator output is monitored with a quantum-noise-limited amplifier and further analysed to generate a clock signal. We show that the quantum clock, near zero temperature, can be partly driven by entropy reduction through measurement, and is necessarily subject to quantum noise. Weak continuous measurement induces sustained coherent oscillations (with fluctuating period) in the conditional moments. Strong continuous measurement leads to an aperiodic cycle of quantum jumps. Both regimes constitute a clock with a signal extracted from the observed measurement current. This signal is analysed to demonstrate the relation between clock period noise and dissipated power for measurement-driven quantum clocks. We show that the thermodynamic limit of clock accuracy is the rates of energy dissipation and entropy generation. |
Friday, March 10, 2023 11:54AM - 12:06PM Author not Attending |
Z02.00003: Implementation of a coherent feedback clock using superconducting resonators Stefan Zeppetzauer, Leonardo A Morais, Xin HE, Gerard J Milburn, Arkady Fedorov Clocks play an integral part in a variety of applications but have recently drawn interest in the context of fundamental questions such as the connection between time and thermodynamics and the limits of time keeping. From a thermodynamic point of view, a clock is a nonlinear dissipative system that relies on the increase in entropy to keep track of time. It was recently shown that the resolution of a periodic clock is directly proportional to the energy dissipated per cycle. A good clock, both classical and quantum, therefore, necessitates a high rate of energy dissipation. |
Friday, March 10, 2023 12:06PM - 12:18PM |
Z02.00004: Entanglement entropy of highly excited eigenstates of SU(2) symmetric systems Rohit Patil, Lucas Hackl, Marcos Rigol It has been recently conjectured that the average entanglement entropy of highly excited eigenstates of many-body Hamiltonians can be used as a diagnostic of quantum chaos and integrability [1]. In quantum chaotic systems, the leading term exhibits a volume-law behavior with a constant coefficient, while in integrable systems the leading term exhibits a volume-law behavior with a coefficient that depends on the ratio between the sizes of the subsystem and the entire system [2]. Furthermore, in quantum chaotic systems, the first subleading correction has been found to signal the presence of conservation laws such as particle-number [3] and energy [4] conservation. In this work, we study the entanglement entropy of highly excited eigenstates of SU(2) symmetric systems to unveil the effect of noncommuting conservation laws. We show that while such a symmetry does not change the leading order behavior of the entanglement entropy, it does change the subleading corrections. We discuss the nature of those changes using numerical and analytical calculations. |
Friday, March 10, 2023 12:18PM - 12:30PM |
Z02.00005: Quantum Cross Entropy in Integrated Fluctuation Theorems Tharon Holdsworth, Naoki Yamamoto, Prineha Narang, Akira Sone We discuss the role of quantum cross entropy from the perspective of integrated fluctuation |
Friday, March 10, 2023 12:30PM - 12:42PM |
Z02.00006: Quantum Information Scrambling in Nonlinear Systems Akram Touil, Sebastian Deffner Quantum information scrambling describes the spread and delocalization of quantum information throughout information bearing degrees of freedom, such that the information becomes irretrievable by means of local measurements. We study this phenomenon in harmonic oscillators with nonlinear coupling. In particular, we study the behavior of Out-of-Time Ordered Correlators to analytically quantify for which parameters of the Hamiltonian the dynamics exhibit scrambling or quantum chaos. We illustrate our results in models that are classically chaotic and represent a reduction of Yang-Mills-Higgs theory. |
Friday, March 10, 2023 12:42PM - 12:54PM |
Z02.00007: Testing quantum microscopic reversibility using quantum optics Hyukjoon Kwon, Myungshik Kim, Marco Bellini, Alessandro Zavatta, Nicola Biagi, Saverio Francesconi Quantum mechanics can be dramatically different from classical physics as quantum states can be in superposition, while quantum optics has provided a promising platform for exploring quantum natures in the microscopic regime. Recently, it has been actively studied how quantum coherence changes the laws of thermodynamics from both thermodynamics and quantum information perspectives. We propose and experimentally test quantum modification for the principle of microscopic reversibility, a symmetry relation between forward and backward state transitions when a system is interacting with a thermal heat bath. We show that quantum modification plays a critical role in the low-temperature limit, while the quantum-to-classical transition occurs at a high temperature. The experimental demonstration is done in an optical setup by interacting coherent states with thermal states using a beam-splitter, followed by heterodyne detection. |
Friday, March 10, 2023 12:54PM - 1:06PM |
Z02.00008: Doing work and exchanging heat on a system through collisions. Felipe Barra We study the state change in an N-level system induced by collisions with moving massive particles with d-internal levels. The relation between the width of the wave packet of the incident massive particle and the energy level spacing determine if populations and coherences evolve coupled or uncoupled. In the latter case, the target system decoheres as identical consecutive collisions occur [1]. If narrow (in momentum space) wave packets have average momentum distributed with the effusion distribution, the target system thermalizes. The energy exchange can be interpreted as heat. In the limit of very broad wave packets, the collision induces a change of energy but keeps the entropy unchanged. The collision performs work on the target system [2]. These results show that thermodynamic processes can be implemented in collision experiments. We use this physical description to implement a computational thermostat [3]. |
Friday, March 10, 2023 1:06PM - 1:18PM |
Z02.00009: Current fluctuations in open quantum systems: Bridging the gap between quantum continuous measurements and full counting statistics Michael J Kewming, Mark T Mitchison, Gabriel T Landi The probabilistic nature of quantum measurements is central to the deep philosophical questions regarding the foundations of quantum mechanics. It is also of great practical importance, since experimenters can only observe quantum systems indirectly through these measurements. One particularly important scenario is that of continuous measurements, where information about the system is available in the form of an output current, a classical time series which is fundamentally stochastic in nature. The theory of continous quantum measurements is very mature, particulary from the perspective of quantum optics. On the other hand, condensed matter physicists, often use full counting statistics and scattering theory to describe counting measurements, and their statistics using the cumulant generating function. In this talk, I will show how these two concepts can be bridged such that both frameworks can be leveraged simultaneously to better study, and compute, the statistical properties of quantum measurements. |
Friday, March 10, 2023 1:18PM - 1:30PM |
Z02.00010: Universal Scaling Bounds on a Quantum Heat Current Shunsuke Kamimura, Kyo Yoshida, Yasuhiro Tokura, Yuichiro Matsuzaki Recently, an extension of thermodynamics to quantum systems, quantum thermodynamics, is intensely studied not only for a fundamental understanding of quantum systems, but also for industrial applications. In particular, for quantum thermodynamic devices such as quantum heat engines that generate a power output, a heat current is an important resource for their quantum-enhanced performances. |
Friday, March 10, 2023 1:30PM - 1:42PM |
Z02.00011: Rabi enhanced tunneling from solid-state spin qubits: a Lindblad equation for Rabi driven spins in tunneling contact with a reservoir Emily A Townsend, Joshua Pomeroy, Garnett W Bryant Lindblad equations describe the dissipative dynamics of a quantum system interacting with a (typically larger and often memoryless) second system such as a thermal bath. When the system Hamiltonian is not time dependent a complete set of its eigenstates can be used as a basis for expanding the system-bath interaction Hamiltonian, and there is a standard method for obtaining a Lindblad equation by tracing over the bath. |
Friday, March 10, 2023 1:42PM - 1:54PM |
Z02.00012: Electron induced nanoscale nuclear spin relaxation probed by hyperpolarization injection William S Beatrez, Arjun Pillai, Otto Janes, Dieter Suter, Ashok Ajoy We report on experiments that quantify the role of a central electronic spin as a relaxation source for nuclear spins in its nanoscale environment. Our strategy exploits hyperpolarization injection from the electron as a means to controllably probe an increasing number of nuclear spins in the bath, and subsequently interrogate them with high fidelity. Our experiments are focused on a model system of a nitrogen vacancy (NV) center electronic spin surrounded by several hundred 13C nuclear spins. We observe that the 13C transverse spin relaxation times vary significantly with the extent of hyperpolarization injection, allowing the ability to measure the influence of electron mediated relaxation extending over several nanometers. These results suggest interesting new means to spatially discriminate nuclear spins in a nanoscale environment, and have direct relevance to dynamic nuclear polarization and quantum sensors and memories constructed from hyperpolarized nuclei. |
Friday, March 10, 2023 1:54PM - 2:06PM Author not Attending |
Z02.00013: Measurement induced entanglement phase transitions in monitored 1D spin chains Monalisa Singh Roy, Jonathan Ruhman, Emanuele G Dalla Torre, Efrat Shimshoni Entanglement phase transitions have attracted immense attention in recent years, especially in the context of monitored quantum circuits. In such systems, the dynamics due to unitary evolution competes with the localizing effects of measurements. The phase transition of a quantum system between a trivial volume-law phase of entanglement entropy – in case of weak monitoring, into a quantum Zeno-like phase for frequent and/or strong measurements where the entanglement entropy obeys area-law, is well known in many integrable models with unitary dynamics. However recently a critical phase with a logarithmic scaling of the entanglement entropy in a class of integrable models has been identified, in the presence of dissipation. |
Friday, March 10, 2023 2:06PM - 2:18PM Author not Attending |
Z02.00014: Floquet engineering of correlated states by the Ponderomotive potential Zhiyuan Sun The Ponderomotive force is a second order DC force that a particle feels in an inhomogenenous AC field. The effective potential for this force may be called the Ponderomotive potential. We generalize the notion of Ponderomotive potential to periodically driven systems and propose it as a convenient tool to engineer their properties beyond the single particle level. For example, the Ponderomotive potential from coherent incident light may be used to selectively enhance or suppress excitonic order and charge/spin density wave, to steer order parameters between (almost) degenerate states, and to generate interactions on demand such as attractive ones. |
Follow Us |
Engage
Become an APS Member |
My APS
Renew Membership |
Information for |
About APSThe American Physical Society (APS) is a non-profit membership organization working to advance the knowledge of physics. |
© 2024 American Physical Society
| All rights reserved | Terms of Use
| Contact Us
Headquarters
1 Physics Ellipse, College Park, MD 20740-3844
(301) 209-3200
Editorial Office
100 Motor Pkwy, Suite 110, Hauppauge, NY 11788
(631) 591-4000
Office of Public Affairs
529 14th St NW, Suite 1050, Washington, D.C. 20045-2001
(202) 662-8700