Pub Date : 2020-11-17DOI: 10.1103/PhysRevResearch.3.023190
Oscar Emil Sommer, F. Piazza, D. J. Luitz
We show that current noisy quantum computers are ideal platforms for the simulation of quantum many-body dynamics in generic open systems. We demonstrate this using the IBM Quantum Computer as an experimental platform for confirming the theoretical prediction from [Phys. Rev. Lett.124, 100604 (2020)] of an emergent hierarchy of relaxation timescales of many-body observables involving different numbers of qubits. Using different protocols, we leverage the intrinsic dissipation of the machine responsible for gate errors, to implement a quantum simulation of generic (i.e. structureless) local dissipative interactions.
{"title":"Many-body hierarchy of dissipative timescales in a quantum computer","authors":"Oscar Emil Sommer, F. Piazza, D. J. Luitz","doi":"10.1103/PhysRevResearch.3.023190","DOIUrl":"https://doi.org/10.1103/PhysRevResearch.3.023190","url":null,"abstract":"We show that current noisy quantum computers are ideal platforms for the simulation of quantum many-body dynamics in generic open systems. We demonstrate this using the IBM Quantum Computer as an experimental platform for confirming the theoretical prediction from [Phys. Rev. Lett.124, 100604 (2020)] of an emergent hierarchy of relaxation timescales of many-body observables involving different numbers of qubits. Using different protocols, we leverage the intrinsic dissipation of the machine responsible for gate errors, to implement a quantum simulation of generic (i.e. structureless) local dissipative interactions.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"41 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81615636","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-17DOI: 10.1103/PhysRevA.102.053321
Changhun Oh, Hyukjoon Kwon, Liang Jiang, M. Kim
Atomic interferometers have been studied as a promising device for precise sensing of external fields. Among various configurations, a particular configuration with a butterfly-shaped geometry has been designed to sensitively probe field gradients. We introduce a Stern-Gerlach (SG) butterfly interferometer by incorporating magnetic field in the conventional butterfly-shaped configuration. Atomic trajectories of the interferometer can be flexibly adjusted by controlling magnetic fields to increase the sensitivity of the interferometer, while the conventional butterfly interferometer using Raman transitions can be understood as a special case. We also show that the SG interferometer can keep high contrast against a misalignment in position and momentum caused by the field gradient.
{"title":"Field-gradient measurement using a Stern-Gerlach atomic interferometer with butterfly geometry","authors":"Changhun Oh, Hyukjoon Kwon, Liang Jiang, M. Kim","doi":"10.1103/PhysRevA.102.053321","DOIUrl":"https://doi.org/10.1103/PhysRevA.102.053321","url":null,"abstract":"Atomic interferometers have been studied as a promising device for precise sensing of external fields. Among various configurations, a particular configuration with a butterfly-shaped geometry has been designed to sensitively probe field gradients. We introduce a Stern-Gerlach (SG) butterfly interferometer by incorporating magnetic field in the conventional butterfly-shaped configuration. Atomic trajectories of the interferometer can be flexibly adjusted by controlling magnetic fields to increase the sensitivity of the interferometer, while the conventional butterfly interferometer using Raman transitions can be understood as a special case. We also show that the SG interferometer can keep high contrast against a misalignment in position and momentum caused by the field gradient.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"88709551","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-17DOI: 10.1201/9781003078265-13
M. Rogalski, S. Palmer
INTRODUCTION Nuclear radiation can be broadly classified into three categories. These three categories are labeled with the first three letters of the Greek alphabet: α (alpha), β (beta) and γ (gamma). Alpha radiation consists of a stream of fast-moving helium nuclei (two protons and two neutrons). As such, an alpha particle is relatively heavy and carries two positive electrical charges. Beta radiation consists of fast-moving electrons or positrons (an antimatter electron). A beta particle is much lighter than an alpha, and carries one unit of charge. Gamma radiation consists of photons, which are without mass and carry no charge. X-rays are also photons, but carry less energy than gammas.
{"title":"Nuclear Radiation","authors":"M. Rogalski, S. Palmer","doi":"10.1201/9781003078265-13","DOIUrl":"https://doi.org/10.1201/9781003078265-13","url":null,"abstract":"INTRODUCTION Nuclear radiation can be broadly classified into three categories. These three categories are labeled with the first three letters of the Greek alphabet: α (alpha), β (beta) and γ (gamma). Alpha radiation consists of a stream of fast-moving helium nuclei (two protons and two neutrons). As such, an alpha particle is relatively heavy and carries two positive electrical charges. Beta radiation consists of fast-moving electrons or positrons (an antimatter electron). A beta particle is much lighter than an alpha, and carries one unit of charge. Gamma radiation consists of photons, which are without mass and carry no charge. X-rays are also photons, but carry less energy than gammas.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"140 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76616465","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-17DOI: 10.1103/PhysRevApplied.15.064029
I. Takmakov, P. Winkel, F. Foroughi, L. Planat, D. Gusenkova, M. Spiecker, D. Rieger, L. Grünhaupt, A. V. Ustinov, W. Wernsdorfer, I. Pop, N. Roch
Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here we employ this effect over two orders of magnitude in readout power, made possible by the unique combination of a dimer Josephson junction array amplifier with a large dynamic range, and the fact that the readout of our granular aluminum fluxonium artificial atom remained quantum-non-demolition (QND) at relatively large photon numbers in the readout resonator, up to $overline{n} = 110$. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout resonator response time $2/kappa$, where $kappa$ is the bandwidth of the readout resonator.
{"title":"Minimizing the Discrimination Time for Quantum States of an Artificial Atom","authors":"I. Takmakov, P. Winkel, F. Foroughi, L. Planat, D. Gusenkova, M. Spiecker, D. Rieger, L. Grünhaupt, A. V. Ustinov, W. Wernsdorfer, I. Pop, N. Roch","doi":"10.1103/PhysRevApplied.15.064029","DOIUrl":"https://doi.org/10.1103/PhysRevApplied.15.064029","url":null,"abstract":"Fast discrimination between quantum states of superconducting artificial atoms is an important ingredient for quantum information processing. In circuit quantum electrodynamics, increasing the signal field amplitude in the readout resonator, dispersively coupled to the artificial atom, improves the signal-to-noise ratio and increases the measurement strength. Here we employ this effect over two orders of magnitude in readout power, made possible by the unique combination of a dimer Josephson junction array amplifier with a large dynamic range, and the fact that the readout of our granular aluminum fluxonium artificial atom remained quantum-non-demolition (QND) at relatively large photon numbers in the readout resonator, up to $overline{n} = 110$. Using Bayesian inference, this allows us to detect quantum jumps faster than the readout resonator response time $2/kappa$, where $kappa$ is the bandwidth of the readout resonator.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"89 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-17","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"76189836","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-16DOI: 10.1103/PhysRevA.103.052438
Q. P. Stefano, I. Perito, Juan Jos'e Miguel Varga, Lorena Reb'on, Claudio Iemmi
The temporal evolution of a quantum system can be characterized by quantum process tomography, a complex task that consumes a number of physical resources scaling exponentially with the number of subsystems. An alternative approach to the full reconstruction of a quantum channel allows selecting which coefficient from its matrix description to measure, and how accurately, reducing the amount of resources to be polynomial. The possibility of implementing this method is closely related to the possibility of building a complete set of mutually unbiased bases (MUBs) whose existence is known only when the dimension of the Hilbert space is the power of a prime number. However, an extension of the method that uses tensor products of maximal sets of MUBs, has been introduced recently. Here we explicitly describe how to implement this algorithm to selectively and efficiently estimate any parameter characterizing a quantum process in a non-prime power dimension, and we conducted for the first time an experimental verification of the method in a Hilbert space of dimension $d=6$. That is the small space for which there is no known a complete set of MUBs but it can be decomposed as a tensor product of two other Hilbert spaces of dimensions $D_1=2$ and $D_2=3$, for which a complete set of MUBs is known. The $6$-dimensional states were codified in the discretized transverse momentum of the photon wavefront. The state preparation and detection stages are dynamically programmed with the use of only-phase spatial light modulators, in a versatile experimental setup that allows to implement the algorithm in any finite dimension.
{"title":"Experimental characterization of quantum processes: A selective and efficient method in arbitrary finite dimensions","authors":"Q. P. Stefano, I. Perito, Juan Jos'e Miguel Varga, Lorena Reb'on, Claudio Iemmi","doi":"10.1103/PhysRevA.103.052438","DOIUrl":"https://doi.org/10.1103/PhysRevA.103.052438","url":null,"abstract":"The temporal evolution of a quantum system can be characterized by quantum process tomography, a complex task that consumes a number of physical resources scaling exponentially with the number of subsystems. An alternative approach to the full reconstruction of a quantum channel allows selecting which coefficient from its matrix description to measure, and how accurately, reducing the amount of resources to be polynomial. The possibility of implementing this method is closely related to the possibility of building a complete set of mutually unbiased bases (MUBs) whose existence is known only when the dimension of the Hilbert space is the power of a prime number. However, an extension of the method that uses tensor products of maximal sets of MUBs, has been introduced recently. Here we explicitly describe how to implement this algorithm to selectively and efficiently estimate any parameter characterizing a quantum process in a non-prime power dimension, and we conducted for the first time an experimental verification of the method in a Hilbert space of dimension $d=6$. That is the small space for which there is no known a complete set of MUBs but it can be decomposed as a tensor product of two other Hilbert spaces of dimensions $D_1=2$ and $D_2=3$, for which a complete set of MUBs is known. The $6$-dimensional states were codified in the discretized transverse momentum of the photon wavefront. The state preparation and detection stages are dynamically programmed with the use of only-phase spatial light modulators, in a versatile experimental setup that allows to implement the algorithm in any finite dimension.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"19 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-16","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"90688387","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Pub Date : 2020-11-13DOI: 10.21203/rs.3.rs-107899/v1
Jongmin Lee, G. Biedermann, John P. Mudrick, E. Douglas, Y. Jau
We present a demonstration of keeping a cold-atom ensemble within a sub-millimeter diameter hole in a transparent membrane.Based on the effective beam diameter of the magneto-optical trap (MOT) given by the hole diameter (d = 400 μm), we measurean atom number that is 105 times higher than the predicted value using the conventional d6 scaling rule. Atoms trapped bythe membrane MOT are cooled down to 10 μK with sub-Doppler cooling. Such a device can be potentially coupled to thephotonic/electronic integrated circuits that can be fabricated in the membrane device representing a step toward the atom trapintegrated platform.
{"title":"Membrane MOT: Trapping Dense Cold Atoms in a Sub-Millimeter Diameter Hole of a Microfabricated Membrane Device","authors":"Jongmin Lee, G. Biedermann, John P. Mudrick, E. Douglas, Y. Jau","doi":"10.21203/rs.3.rs-107899/v1","DOIUrl":"https://doi.org/10.21203/rs.3.rs-107899/v1","url":null,"abstract":"\u0000 We present a demonstration of keeping a cold-atom ensemble within a sub-millimeter diameter hole in a transparent membrane.Based on the effective beam diameter of the magneto-optical trap (MOT) given by the hole diameter (d = 400 μm), we measurean atom number that is 105 times higher than the predicted value using the conventional d6 scaling rule. Atoms trapped bythe membrane MOT are cooled down to 10 μK with sub-Doppler cooling. Such a device can be potentially coupled to thephotonic/electronic integrated circuits that can be fabricated in the membrane device representing a step toward the atom trapintegrated platform.","PeriodicalId":8484,"journal":{"name":"arXiv: Quantum Physics","volume":"28 1","pages":""},"PeriodicalIF":0.0,"publicationDate":"2020-11-13","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"81909171","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":0,"RegionCategory":"","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}