我在乳胶中无法将 qcircuit 图居中。我正在使用 revtex4-1。
我尝试过使用\begin{figure*} ... \end{figure*}，但是它并没有将图表渲染在文档的中心，而是渲染在某一列中，尽管没有抛出任何错误，但它根本就没有绘制。
这是正在制作的图表。目前它太宽了，并且会卡在实际文档的另一列文本中。
正在绘制的图表看起来应该是这样的：
相反，我编译的文档中只有一个空白区域，如果将图表限制在单个列中，该区域就会出现：
\documentclass[%
reprint,
nofootinbib,
amsmath,amssymb,
aps,
]{revtex4-1}
\usepackage{graphicx}
\usepackage{dcolumn}
\usepackage{bm}
\usepackage{hyperref}
\usepackage{braket}
\usepackage{amssymb}
\usepackage{amsthm}
\usepackage{mathtools}
\usepackage{tikz}
\usepackage{circuitikz}
\input{Qcircuit}
\begin{document}
\begin{figure*}
\centerline{
\Qcircuit @C=1em @R=.7em @!R{
\lstick{\ket{j_1}} & \gate{H} & \gate{R_2} & \qw & \dots & & \qw & \gate{R_n}\ & \qw & \qw \\
\lstick{\ket{j_2}} & \qw & \ctrl{-1} & \qw & \dots & & \qw & \qw & \gate{H} & \qw & \dots & & \qw & \gate{R_{n-1}} & \qw & \qw\\
}}
\end{figure*}
\end{document}
下面粘贴的是 Qcircuit.tex
\ProvidesPackage{qcircuit}[2014/06/29]
\RequirePackage{xy}
\DeclareOption{braket}{
\newcommand{\bra}[1]{\ensuremath{\left\langle{#1}\right\vert}}
\newcommand{\ket}[1]{\ensuremath{\left\vert{#1}\right\rangle}}
}
\DeclareOption{qm}{
\newcommand{\ip}[2]{\ensuremath{\left\langle{#1}\right\vert{#2}\rangle}}
\newcommand{\melem}[3]{\ensuremath{\left\langle{#1}\right\vert{#2}\vert{#3}\rangle}}
\newcommand{\expval}[1]{\ensuremath{\left\langle #1 \right\rangle}}
\newcommand{\op}[2]{\ensuremath{\vert{#1}\rangle\langle{#2}\vert}}
}
\ProcessOptions\relax
\xyoption{matrix}
\xyoption{frame}
\xyoption{arrow}
\xyoption{arc}
\usepackage{ifpdf}
\ifpdf
\else
\PackageWarningNoLine{Qcircuit}{Qcircuit is loading in Postscript mode. The Xy-pic options ps and dvips will be loaded. If you wish to use other Postscript drivers for Xy-pic, you must modify the code in Qcircuit.tex}
% The following options load the drivers most commonly required to
% get proper Postscript output from Xy-pic. Should these fail to work,
% try replacing the following two lines with some of the other options
% given in the Xy-pic reference manual.
\xyoption{ps}
\xyoption{dvips}
\fi
% The following resets Xy-pic matrix alignment to the pre-3.8 default, as
% required by Qcircuit.
\entrymodifiers={!C\entrybox}
\newcommand{\qw}[1][-1]{\ar @{-} [0,#1]}
% Defines a wire that connects horizontally. By default it connects to the object on the left of the current object.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\qwx}[1][-1]{\ar @{-} [#1,0]}
% Defines a wire that connects vertically. By default it connects to the object above the current object.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\qwa}[1][-1]{\ar @{<-} [0,#1]}
% Defines a wire that connects horizontally with an arrow. By default it makes an end wire with an arrow indicating the end of the circuit.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\cw}[1][-1]{\ar @{=} [0,#1]}
% Defines a classical wire that connects horizontally. By default it connects to the object on the left of the current object.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\cwx}[1][-1]{\ar @{=} [#1,0]}
% Defines a classical wire that connects vertically. By default it connects to the object above the current object.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\cwa}[1][-1]{\ar @{<=} [0,#1]}
% Defines a classical wire that connects horizontally with an arrow. By default it makes an end wire with an arrow indicating the end of the circuit.
% WARNING: Wire commands must appear after the gate in any given entry.
\newcommand{\cds}[2]{*+<1em,.9em>{\hphantom{#2}} \POS [0,0].[#1,0]="e",!C *{#2};"e"+ R \qw}
% Allows the insertion of text without a box and exands circuit around this text.
% This is useful for such things as ... to indicate a generalized circuit.
\newcommand{\gate}[1]{*+<.6em>{#1} \POS ="i","i"+UR;"i"+UL **\dir{-};"i"+DL **\dir{-};"i"+DR **\dir{-};"i"+UR **\dir{-},"i" \qw}
% Boxes the argument, making a gate.
\newcommand{\sgate}[2]{\gate{#1} \qwx[#2]}
% Creates a gate and a qwx wire going #2 spots below, for a gate split over
% non-adjacent rows
\newcommand{\meter}{*=<1.8em,1.4em>{\xy ="j","j"-<.778em,.322em>;{"j"+<.778em,-.322em> \ellipse ur,_{}},"j"-<0em,.4em>;p+<.5em,.9em> **\dir{-},"j"+<2.2em,2.2em>*{},"j"-<2.2em,2.2em>*{} \endxy} \POS ="i","i"+UR;"i"+UL **\dir{-};"i"+DL **\dir{-};"i"+DR **\dir{-};"i"+UR **\dir{-},"i" \qw}
% Inserts a measurement meter.
% In case you're wondering, the constants .778em and .322em specify
% one quarter of a circle with radius 1.1em.
% The points added at + and - <2.2em,2.2em> are there to strech the
% canvas, ensuring that the size is unaffected by erratic spacing issues
% with the arc.
\newcommand{\metersymb}{\xy ="j","j"-<.778em,.322em>;{"j"+<.778em,-.322em> \ellipse ur,_{}},"j"-<0em,.4em>;p+<.5em,.9em> **\dir{-},"j"+<2.2em,2.2em>*{},"j"-<2.2em,2.2em>*{} \endxy}
% A longer meter
\newcommand{\meterB}[1]{*=<1.8em,2.6em>{\xy 0;<0em,-.8em>:
0*{\begingroup
\everymath{\scriptstyle}
\tiny #1 \endgroup},<0em,.7em>*{\xy ="j","j"-<.778em,-.322em>;{"j"+<.778em,.322em> \ellipse ur,_{}},"j"-<0em,-.2em>;p+<.5em,.9em> **\dir{-},"j"+<2.2em,2.2em>*{},"j"-<2.2em,2.2em>*{} \endxy}
\endxy} \POS ="i","i"+UR;"i"+UL **\dir{-};"i"+DL **\dir{-};"i"+DR **\dir{-};"i"+UR **\dir{-},"i" \qw}
% A meter that allows for a measurement operator to be added below
\newcommand{\smeterB}[2]{\meterB{#1} \qwx[#2] \qw}
% A split meter that allows for a measurement operator to be split over non-
% adjacent rows
\newcommand{\measure}[1]{*+[F-:<.9em>]{#1} \qw}
% Inserts a measurement bubble with user defined text.
\newcommand{\measuretab}[1]{*{\xy*+<.6em>{#1}="e";"e"+UL;"e"+UR **\dir{-};"e"+DR **\dir{-};"e"+DL **\dir{-};"e"+LC-<.5em,0em> **\dir{-};"e"+UL **\dir{-} \endxy} \qw}
% Inserts a measurement tab with user defined text.
\newcommand{\measureD}[1]{*{\xy*+=<0em,.1em>{#1}="e";"e"+UR+<0em,.25em>;"e"+UL+<-.5em,.25em> **\dir{-};"e"+DL+<-.5em,-.25em> **\dir{-};"e"+DR+<0em,-.25em> **\dir{-};{"e"+UR+<0em,.25em>\ellipse^{}};"e"+C:,+(0,1)*{} \endxy} \qw}
% Inserts a D-shaped measurement gate with user defined text.
\newcommand{\multimeasure}[2]{*+<1em,.9em>{\hphantom{#2}} \qw \POS[0,0].[#1,0];p !C *{#2},p \drop\frm<.9em>{-}}
% Draws a multiple qubit measurement bubble starting at the current position and spanning #1 additional gates below.
% #2 gives the label for the gate.
% You must use an argument of the same width as #2 in \ghost for the wires to connect properly on the lower lines.
\newcommand{\multimeasureD}[2]{*+<1em,.9em>{\hphantom{#2}} \POS [0,0]="i",[0,0].[#1,0]="e",!C *{#2},"e"+UR-<.8em,0em>;"e"+UL **\dir{-};"e"+DL **\dir{-};"e"+DR+<-.8em,0em> **\dir{-};{"e"+DR+<0em,.8em>\ellipse^{}};"e"+UR+<0em,-.8em> **\dir{-};{"e"+UR-<.8em,0em>\ellipse^{}},"i" \qw}
% Draws a multiple qubit D-shaped measurement gate starting at the current position and spanning #1 additional gates below.
% #2 gives the label for the gate.
% You must use an argument of the same width as #2 in \ghost for the wires to connect properly on the lower lines.
\newcommand{\control}{*!<0em,.025em>-=-<.2em>{\bullet}}
% Inserts an unconnected control.
\newcommand{\controlo}{*+<.01em>{\xy -<.095em>*\xycircle<.19em>{} \endxy}}
% Inserts a unconnected control-on-0.
\newcommand{\ctrl}[1]{\control \qwx[#1] \qw}
% Inserts a control and connects it to the object #1 wires below.
\newcommand{\ctrlo}[1]{\controlo \qwx[#1] \qw}
% Inserts a control-on-0 and connects it to the object #1 wires below.
\newcommand{\cctrl}[1]{\control \cwx[#1] \cw}
% Inserts a classical control and connects it to the object #1 wires below.
\newcommand{\cctrlo}[1]{\controlo \cwx[#1] \cw}
% Inserts a classical control-on-0 and connects it to the object #1 wires below.
\newcommand{\targ}{*+<.02em,.02em>{\xy ="i","i"-<.39em,0em>;"i"+<.39em,0em> **\dir{-}, "i"-<0em,.39em>;"i"+<0em,.39em> **\dir{-},"i"*\xycircle<.4em>{} \endxy} \qw}
% Inserts a CNOT target.
\newcommand{\qswap}{*=<0em>{\times} \qw}
% Inserts half a swap gate.
% Must be connected to the other swap with \qwx.
\newcommand{\multigate}[2]{*+<1em,.9em>{\hphantom{#2}} \POS [0,0]="i",[0,0].[#1,0]="e",!C *{#2},"e"+UR;"e"+UL **\dir{-};"e"+DL **\dir{-};"e"+DR **\dir{-};"e"+UR **\dir{-},"i" \qw}
% Draws a multiple qubit gate starting at the current position and spanning #1 additional gates below.
% #2 gives the label for the gate.
% You must use an argument of the same width as #2 in \ghost for the wires to connect properly on the lower lines.
\newcommand{\ghost}[1]{*+<1em,.9em>{\hphantom{#1}} \qw}
% Leaves space for \multigate on wires other than the one on which \multigate appears. Without this command wires will cross your gate.
% #1 should match the second argument in the corresponding \multigate.
\newcommand{\push}[1]{*{#1}}
% Inserts #1, overriding the default that causes entries to have zero size. This command takes the place of a gate.
% Like a gate, it must precede any wire commands.
% \push is useful for forcing columns apart.
% NOTE: It might be useful to know that a gate is about 1.3 times the height of its contents. I.e. \gate{M} is 1.3em tall.
% WARNING: \push must appear before any wire commands and may not appear in an entry with a gate or label.
\newcommand{\gategroup}[6]{\POS"#1,#2"."#3,#2"."#1,#4"."#3,#4"!C*+<#5>\frm{#6}}
% Constructs a box or bracket enclosing the square block spanning rows #1-#3 and columns=#2-#4.
% The block is given a margin #5/2, so #5 should be a valid length.
% #6 can take the following arguments -- or . or _\} or ^\} or \{ or \} or _) or ^) or ( or ) where the first two options yield dashed and
% dotted boxes respectively, and the last eight options yield bottom, top, left, and right braces of the curly or normal variety. See the Xy-pic reference manual for more options.
% \gategroup can appear at the end of any gate entry, but it's good form to pick either the last entry or one of the corner gates.
% BUG: \gategroup uses the four corner gates to determine the size of the bounding box. Other gates may stick out of that box. See \prop.
\newcommand{\inputgroupv}[5]{\POS"#1,1"."#2,1"."#1,1"."#2,1"!C*+<#3>\frm{\{}, \POS"#1,1"."#2,1"."#1,1"."#2,1"*!C!<1.7em,#4>=<0em>{#5}}
% Constructs an input group with label #5 and a grouping { from rows #1 to #2 with #3 and #4 controlling the spacing
\newcommand{\inputgroup}[4]{\POS"#1,1"."#2,1"."#1,1"."#2,1", \POS"#1,1"."#2,1"."#1,1"."#2,1"*!C!<1em,#3>=<0em>{#4}}
% Constructs an input group with label #4 from rows #1 to #2 with #3 controlling the spacing
\newcommand{\inputgrouph}[5]{\POS"#1,1"."#2,1"."#1,1"."#2,1", \POS"#1,1"."#2,1"."#1,1"."#2,1"*!C!<#5,#3>=<0em>{#4}}
% Constructs an input group with label #4 and a grouping /vdots from rows #1 to #2 with #3 and #5 controlling the spacing
\newcommand{\rstick}[1]{*!L!<-.5em,0em>=<0em>{#1}}
% Centers the left side of #1 in the cell. Intended for lining up wire labels. Note that non-gates have default size zero.
\newcommand{\lstick}[1]{*!R!<.5em,0em>=<0em>{#1}}
% Centers the right side of #1 in the cell. Intended for lining up wire labels. Note that non-gates have default size zero.
\newcommand{\ustick}[1]{*!D!<0em,-.5em>=<0em>{#1}}
% Centers the bottom of #1 in the cell. Intended for lining up wire labels. Note that non-gates have default size zero.
\newcommand{\dstick}[1]{*!U!<0em,.5em>=<0em>{#1}}
% Centers the top of #1 in the cell. Intended for lining up wire labels. Note that non-gates have default size zero.
\newcommand{\Qcircuit}{\xymatrix @*=<0em>}
% Defines \Qcircuit as an \xymatrix with entries of default size 0em.
\newcommand{\link}[2]{\ar @{-} [#1,#2]}
% Draws a wire or connecting line to the element #1 rows down and #2 columns forward.
\newcommand{\pureghost}[1]{*+<1em,.9em>{\hphantom{#1}}}
% Same as \ghost except it omits the wire leading to the left.
\endinput
编辑：
我正在使用（我认为）pdfTeX 3.14159265-2.6-1.40.17 (TeX Live 2016/Debian) kpathsea version 6.2.2
答案1
我手边没有 TeX 的工作副本，但以下代码应该允许您将电路排版为单独的图像文件，然后可以以标准方式将其包含在您的文档中。（可能需要根据您的电路调整间距参数。）
\documentclass{standalone}
\input{Qcircuit}% using qcircuit version 2
\begin{document}
\hspace{1em}
\begin{tabular}{c}
\vspace{-.6em}\\
\Qcircuit @C=1em @R=.7em @!R{
\lstick{\ket{j_1}} & \gate{H} & \gate{R_2} & \qw & \dots & & \qw & \gate{R_n}\ & \qw & \qw \\
\lstick{\ket{j_2}} & \qw & \ctrl{-1} & \qw & \dots & & \qw & \qw & \gate{H} & \qw & \dots & & \qw & \gate{R_{n-1}} & \qw & \qw\\
}
\vspace{.2em}\hspace{1.2em}
\\
\end{tabular}
\end{document}
这并没有真正回答你的问题，但如果问题是 Qcircuit 和你的文档的其余部分之间存在一些冲突，那么它应该可以避免这个问题。
总的来说，我还是建议单独编译你的图像。