Computer Science Research Works
http://hdl.handle.net/1903/1593
Mon, 09 Dec 2019 10:04:06 GMT2019-12-09T10:04:06ZDiscontinuity of maximum entropy inference and quantum phase transitions
http://hdl.handle.net/1903/20642
Discontinuity of maximum entropy inference and quantum phase transitions
Chen, Jianxin; Ji, Zhengfeng; Li, Chi-Kwong; Poon, Yiu-Tung; Shen, Yi; Yu, Nengkun; Zeng, Bei; Zhou, Duanlu
In this paper, we discuss the connection between two genuinely quantum phenomena—the
discontinuity of quantum maximum entropy inference and quantum phase transitions at zero
temperature. It is shown that the discontinuity of the maximum entropy inference of local observable
measurements signals the non-local type of transitions, where local density matrices of the ground
state change smoothly at the transition point.Wethen propose to use the quantum conditional
mutual information of the ground state as an indicator to detect the discontinuity and the non-local
type of quantum phase transitions in the thermodynamic limit.
Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.
Mon, 10 Aug 2015 00:00:00 GMThttp://hdl.handle.net/1903/206422015-08-10T00:00:00ZHamiltonian simulation with optimal sample complexity
http://hdl.handle.net/1903/20599
Hamiltonian simulation with optimal sample complexity
Kimmel, Shelby; Lin, Cedric Yen-Yu; Low, Guang Hao; Ozols, Maris; Yoder, Theodore J.
We investigate the sample complexity of Hamiltonian simulation: how many copies of an unknown quantum state are required to simulate a Hamiltonian encoded by the density matrix of that state? We show that the procedure proposed by Lloyd, Mohseni, and Rebentrost [Nat. Phys., 10(9):631–633, 2014] is optimal for this task. We further extend their method to the case of multiple input states, showing how to simulate any Hermitian polynomial of the states provided. As applications, we derive optimal algorithms for commutator simulation and orthogonality testing, and we give a protocol for creating a coherent superposition of pure states, when given sample access to those states. We also show that this sample-based Hamiltonian simulation can be used as the basis of a universal model of quantum computation that requires only partial swap operations and simple single-qubit states.
Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.
Sun, 01 Jan 2017 00:00:00 GMThttp://hdl.handle.net/1903/205992017-01-01T00:00:00ZTrust transfer between contexts
http://hdl.handle.net/1903/19747
Trust transfer between contexts
Buntain, Cody; Golbeck, Jennifer
This paper explores whether trust, developed in one context, transfers into another, distinct context and, if so, attempts to quantify the influence this prior trust exerts. Specifically, we investigate the effects of artificially stimulated prior trust as it transfers across disparate contexts and whether this prior trust can compensate for negative objective information. To study such incidents, we leveraged Berg’s investment game to stimulate varying degrees of trust between a human and a set of automated agents. We then observed how trust in these agents transferred to a new game by observing teammate selection in a modified, four-player extension of the well-known board game, Battleship. Following this initial experiment, we included new information regarding agent proficiency in the Battleship game during teammate selection to see how prior trust and new objective information interact. Deploying these experiments on Amazon’s Mechanical Turk platform further allowed us to study these phenomena across a broad range of participants. Our results demonstrate trust does transfer across disparate contexts and this inter-contextual trust transfer exerts a stronger influence over human behavior than objective performance data. That is, humans show a strong tendency to select teammates based on their prior experiences with each teammate, and proficiency information in the new context seems to matter only when the differences in prior trust between potential teammates are small.
Funding for Open Access provided by the UMD Libraries Open Access Publishing Fund.
Thu, 01 Jan 2015 00:00:00 GMThttp://hdl.handle.net/1903/197472015-01-01T00:00:00ZOn Number Of Partitions Of An Integer Into A Fixed Number Of Positive Integers
http://hdl.handle.net/1903/16351
On Number Of Partitions Of An Integer Into A Fixed Number Of Positive Integers
Oruc, A. Yavuz
This paper focuses on the number of partitions of a positive integer $n$ into $k$ positive summands, where $k$ is an integer between $1$ and $n$. Recently some upper bounds were reported for this number in [Merca14]. Here, it is shown that these bounds are not as tight as an earlier upper bound proved in [Andrews76-1] for $k\le 0.42n$. A new upper bound for the number of partitions of $n$ into $k$ summands is given, and shown to be tighter than the upper bound in [Merca14] when $k$ is between $O(\frac{\sqrt{n}}{\ln n})$ and $n-O(\frac{\sqrt{n}}{\ln n})$. It is further shown that the new upper bound is also tighter than two other upper bounds previously reported in~[Andrews76-1] and [Colman82]. A generalization of this upper bound to number of partitions of $n$ into at most $k$ summands is also presented.
Submitted to Journal of Number Theory.
Wed, 01 Apr 2015 00:00:00 GMThttp://hdl.handle.net/1903/163512015-04-01T00:00:00Z